War Thunder has never made a mechanics change that led to SMALLER explosions.
(The obvious exception to make here is how the game handles torpedoes. Japanese WW2 torpedoes, because they had pure picric acid warheads, actually did go off like bombs when hit (compounded by the pure O2 fuel tank they also had). Other countries’ torpedo warheads were basically inert, like aerial bombs. Gaijin won’t make that differentiation, even though it lists the fillers correctly. So for a while we had torpedoes that went off as if they were all Japanese. Naval players hated that, so they ratcheted the explosion physics in naval down now so almost NO torpedoes high-order when hit at all. A specific factor of WW2 Pacific naval combat just zeroed out, basically because Gaijin couldn’t figure out how to balance it, not for any historical or game limitation.)
But games like this have a problem with shell “dudding” of any kind. People want their shells, etc. to go off when hit, or explode when they hit the ground. If that doesn’t happen, they don’t think, “well, this T-34 shell actually had a 50% successful detonation rate, I was probably unlucky”, they think, “freaking game, how did I miss, is that guy hacking?” Similarly hitting bombs in air and dudding them would be accurate, but since no one would notice, no one would really understand and they’d just blame the game physics.
So, being realistic about games, I think if by luck your 50 cal hits a bomb in the air, it probably SHOULD explode, just so both bomber and bombed know what just happened. That does NOT mean they should detonate while still on the external rack (instead of just being knocked off), or chain-explode the whole stick back up into the bomb bay, as now, which are both stupid things that can’t happen in real life. It would be simple for Gaijin to put in rules to prevent both those behaviors, and they don’t, for rule of cool reasons.
There’s no real debate to be had on what was physically possible here. All the facts needed to say the behaviors I’m talking about could not physically happen to a real bomber in a real situation, are in public domain. This is a gameplay decision, like your example of nukes, and really only needs to be debated as one.