Boxer Hasan Karkardi was banned for six months for taking part but will not appeal against his punishment.
Blackwell had retired after suffering a bleed on the skull in March and spending a week in an induced coma.
But he subsequently sparred with Karkadi and was again left in a coma.
The British Boxing Board of Control said Wilkins' conduct was "detrimental to the interests of boxing".
Wilkins and Karkadi were both set to appeal after releasing a joint statement on Thursday, before the latter changed his decision.
Blackwell was placed in an induced coma in March after losing his British middleweight title fight with Chris Eubank Jr.
Despite not having a licence to fight, and despite him being advised not to return to the ring, Blackwell sparred with Karkardi, 29, on 22 November at a boxing club in Devizes, Wiltshire.
It left Blackwell in a coma for the second time and requiring surgery to reduce swelling on his brain.
A family member has told BBC Sport that although Blackwell is out of the coma he is still unable to walk, and is a year away from making a full recovery.

The SNP said the Ipsos Mori survey for STV was a "sensational" endorsement.
The poll also indicated that the Nationalists would win next May's Holyrood election with 74 seats.
Scottish Labour said it was focusing on what mattered and the Scottish Tories said they would continue to make a positive case for the UK.
The survey, which questioned 1,002 people last week, comes almost a year after Scotland rejected independence by a margin of 55% to 45%.
It is thought to be the first poll to show a majority for "Yes" among all those questioned.
Previous polls in the run-up to the September 2014 vote that showed a majority for independence had excluded those who were undecided.
Half of those questioned for STV said they would like to see another referendum within five years while 58% said they would be in favour of having one in the next 10 years.
Support for the SNP continues to be high in the wake of the party's landslide general election victory north of the border, winning 56 of Scotland's 59 Westminster seats.
The poll found that 55% of those who gave a voting intention would back the Nationalists in the Scottish Parliament constituency vote if the election was held tomorrow.
About a fifth (21%) would vote Labour, with support for the Tories at 12%, Liberal Democrats at 7% and Greens at 3%.
In the list vote, SNP support fell to 50% and backing for the Greens rose to 8%, with the preferences for the other parties remaining the same.
The SNP's business convener Derek Mackay said: "This is a sensational poll for the SNP - it shows not only that people across Scotland support us in huge and growing numbers eight years into government, but that they believe we have a strong record on key issues like health and education."
He added: "It is welcome to see support for independence now stands at over 50 per cent, as people see the SNP in government and at Westminster stand up for Scotland."
A Scottish Labour spokesman said that the party, under the new leadership of Kezia Dugdale, was changing.
He added: "We want people to take another look at Scottish Labour.
"But we know it's too early to be asking people for their votes.
"Over the coming months, we will put Labour's values first and we will focus on the things that matter in people's lives - like the standards in our schools and our hospitals."
The Scottish Conservative Party said it would "always stand up for" the two million people in Scotland who voted "No" in last year's referendum.
A spokesman added: "For its part, rather than revelling in this poll, the SNP needs to focus on the day job.
"While the Scottish government takes Scotland down the constitutional cul-de-sac, education standards have fallen and the police service set up by this SNP government just two years ago is facing breakdown.
"Scotland needs a better way forward, not a step back to yet another referendum."
The pollsters interviewed 1002 people between the 24 and 30 August.  The margin of error was plus or minus three.
Trainer Liam Wilkins will appeal against his licence being withdrawn for the sparring session in November that left retired fighter Nick Blackwell in a coma for the second time in a year.
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Political parties have been reacting to a poll suggesting that 53% of voters in Scotland would back independence if there was another referendum.