No. Term predates the miners' use of it.

The word has several documented strands. The best-attested origin is the sunburned neck of outdoor farm laborers, recorded in the 19th century. Union coal miners really were called rednecks because of their red bandanas, and some popular accounts present this as the origin. The dated evidence puts the miners' use after the farmer sense, so it is better seen as a later use that gave the word extra meaning. The exact earliest origin can't be pinned down with certainty, but the claim that it comes from unionised miners is not supported.

• Early uses, from the 1830s onward, describe poor rural white farmers whose necks were sunburned from outdoor work.
• Dictionaries also record older uses of the word, such as for Scottish Presbyterian dissenters, but their link to the modern word is uncertain.
• Striking miners in the West Virginia Mine Wars wore red bandanas, and the 1921 Battle of Blair Mountain made the name widely known for them.
• Because the sunburn use came first, the miners' use was an addition to the word's meaning rather than its source.
• The term later became a general, often derogatory label for poor rural white Southerners.

The claim confuses a genuine later use with the origin of the word. The miners’ red-bandana identity is documented, but the nineteenth-century rural usage shows that they did not originate “redneck.” The precise original derivation is less certain than this chronology; sunburn is the leading explanation, not an established account of who first coined it.

• The term appeared in the Pontotoc Democrat in Mississippi on August 13, 1891, in a political campaign involving rural voters.
• In 1893, Hubert Shands recorded “red-neck” as a name for poorer inhabitants of rural Mississippi.
• The prevailing scholarly explanation links the rural class label to agricultural workers’ sunburned necks.
• At the 1921 Battle of Blair Mountain, union-supporting miners wore red bandanas as identification and a symbol of solidarity.

1. en.wikipedia.org
2. en.wikipedia.org
3. manifold.open.umn.edu
4. wvminewars.squarespace.com
5. cambridge.org
6. en.wiktionary.org
7. justseeds.org
8. startrader.one

The claim reverses the chronology. The word "redneck" has a documented history going back centuries before the 1920s Appalachian coal wars, first in Scotland and then in the American South as a label for poor, sun-exposed white farmers and labourers. The union miners who wore red bandanas during the West Virginia mine wars are a well-known later episode that strengthened the term's association with white working-class militancy, so the story is partly rooted in real events, but it is not the origin of the word.

• "Red-neck" was used in Scotland from around the 17th century for Presbyterian Covenanters who signed their covenant in red or wore red cloth.
• In the United States the term appears by the 1830s, referring to poor white Southerners whose necks were reddened from field work.
• The word was used as a class-based label for white labourers and small farmers through the 19th century, well before the West Virginia mine wars.
• During the 1921 Battle of Blair Mountain, thousands of unionising coal miners wore red bandanas, and the press and opponents called them "rednecks".
• The miners' red bandana is a real and documented chapter in the word's history, but it is a later use, not its origin.

The claim that the term 'rednecks' comes from unionised coal workers is partly true but not entirely accurate. The term existed as early as the 1830s, originally referring to poor white laborers, particularly farmers with sunburned necks. However, during the early 20th century, especially in the 1920s, unionised coal miners in Appalachia adopted red bandanas as a symbol of solidarity and union membership. This association led to the term 'redneck' being widely used to describe these miners, particularly during the Mine Wars and the Battle of Blair Mountain in 1921. While the term did not originate with coal miners, their use of red bandanas popularised and gave new meaning to the term, linking it to labor rights and union solidarity.

• The term 'redneck' was used as early as the 1830s to refer to poor white rural laborers, especially farmers with sunburned necks.
• During the 1920s, unionised coal miners in Appalachia wore red bandanas as a symbol of solidarity, leading to the term being associated with them.
• The Mine Wars, including the Battle of Blair Mountain (1921), saw striking miners referred to as 'rednecks' by the press and coal operators.
• The term was already in use before the coal miners adopted it, but their use popularised and changed its meaning to include union solidarity.
• Coal operators sometimes used the term to imply communist or socialist ties, trying to discredit the miners.

1. National Coal Board Labour Staff Association en.wikipedia.org
2. Redneck - Wikipedia en.wikipedia.org
3. Cape Town Municipal Workers' Association en.wikipedia.org
4. The Unexpected, Radical Roots of ‘Redneck’ | The Daily Yonder dailyyonder.com
5. National Workers Union (Trinidad & Tobago) en.wikipedia.org
6. Why the Term “Redneck” Defies Simplistic Origin Stories slate.com
7. Rednecks – Subcultures and Sociology haenfler.sites.grinnell.edu
8. ‘Rednecks’ and their ties to the Battle of Blair Mountain | WBOY.com wboy.com