It's not going to happen. The requirements are not considered a problem by the system, since judges exercise discretion and there is no pattern of abuse where people are getting sentences over 2 years for matters that are traditionally disposed of with a CWOF or minor sentence.
The only problem the 2.5 year standard MA creates is the federal DQ, and there is no way the politicians are going to take a stance that is concurrently "pro gun" and "soft on crime". It might happen if minorities were systematically getting 2.5 years for offenses white kids from the suburbs are getting CWOFed for, but that's not really happening. In fact, the 2.5 year standard helps the legal profession since the threat of jail time is what assures the legal profession that people will spend their life savings on representation, even if they are just pleading guilty, rather than go pro-se.
Another unfortunate aspect of this federal prohibition is that the feds do NOT recognize a FLRB state level relief from disabilities, and will NOT remove someone from the NICS denial list even if they provide proof the state granted an FLRB review for a 2.5 year misdemeanor.