For Son of AWB to come to pass a substantial number of discrete events will have to happen. Whilst possible, it is very improbable that ALL these would occur at least during the first term.
Political desire
There will need to be, in Congress, Senate and the White House an overwhelming desire by a sufficient number of influential actors to pass a new AWB. Yes there are a number, Pelosi, Biden et-al however, one of the main potential architects and flag wavers, Kennedy is unlikely to be able to, due to health.
Will to spend political capital
The actors will need to be willing to spend substantial amounts of limited internal political capital (favours/funding/back scratch/pork/horse trade/etc) to raise, draft, rinse and repeat, etc any bill. The "spend" wound have to be thrown around like a drunken sailor on shore leave. It would have to take precedence over almost any other bill and would have to be sold at every stage.
This would be amplified enormously with external "capital", every constituent of every one of the fat controllers will be screaming that it's NOT F&*$ING important, what about the economy, Health care, War, deflation, inflation, 401K, foreclosures, lay offs etc etc.
Change in the Supreme Court
The SC is inherently conservative, that's conservative with a small C. They took over 200 years to make the first substantive ruling on 2A and to overturn such a substantial ruling in less than 4 years is anathema to any judge. To even have the possibility would require a massive sea change in the structure of the SC. Unless the politicals decide to stuff the SC from 9 to say 20 and successfully mange to get the additional 11 in through the vetting process AND the newbies (who now have life tenure) actually vote the way they are supposed to, no changes. If the current 9 change it is statistically likely that we would have 3 "liberals" leave and be replaced like for like. No changes.
Change in the personal political landscape
There would have to be a sweeping change in the belief system of many Americans for an outright assault on 2A. Statistically and even the Brady Campaign accept this, most Americans accept 2A as it is written and believed and see no need to change. They are worried about their families, jobs, health and the economy and demand the pols focus in that. An outright assault on 2A consuming a massive amount of the political process during this time will not be tolerated.
These 4 items are not exhaustive and there are more issues that will impact.
Now, each of these factors COULD come to fruition but for ALL to occur, particularly in the current commercial/personal/political/economic cycle makes it very UNLIKELY.
It is PROBABLE, that as a sop to certain single issue politicians, AWB II may be raised then allowed to die gracefully in committee. "Guys/Gals, look we tried but you now how it is, don't worry we'll keep looking at it"
Now 4 years time.......