Nope.
Taxes can't be vacated or reduced by a bankruptcy court, with a few exceptions for back taxes older than three years.
The IRS allows companies to carry forward net operating losses from previous years to offset future tax liability, but that's available to everyone, not just airlines or companies who declare bankruptcy. Individuals also can carry over certain losses on investments, so it's not just a corporate perk...
The only airline-specific piece of legislation I can recall in the last 20 years was a provision which allowed airlines to extend out the timeframe in which they had to make up for underfunding. It didn't relieve them of present or future liability -- it simply allowed them to contribute a little less over a longer time to make up for projected shortfalls in funding for future liabilities. It was also subjective -- live pensions had one timeframe while distress terminated pensions had a longer timeframe, which wound up penalizing carriers like AA who hadn't distress terminated their plans...