Asgorath
Explorer
This hypothetical situation that both [MENTION=6921966]Asgorath[/MENTION] and Jeremy Crawford have brought up as a problem with the interpretation that allows a shield master to bonus action shove first isn't actually a problem. If the only action you take on your turn is to shove a creature, then it most certainly counts as taking the Attack action. Since that's the situation we're talking about, none of the things you bring up in your post about what happens after I've shoved a creature matter because, according to the example given, at that point, I've been incapacitated.
Where's the rule that lets you go back in time and change your bonus action to an action instead? Given the fact that the Shield Master shove has a trigger of taking the Attack action first, how did you even do the bonus action first? The Sage Advice compendium is quite clear that this isn't supported by the rules, and I'm not aware of any rule that lets you retroactively change a bonus action to an action if something happens that prevents you from taking your action.
He changed his mind about his interpretation. I'm not sure what "massive amount of evidence" you're talking about other than him changing his mind, though. What we disagree about is that you think I'm making an error in interpretation. My view is that both interpretations are valid. I know which one I prefer, however.
Again, we can agree to disagree about what happened here, though I think his explanation of the original tweet (i.e. he replied when he did not have the books in front of him and then promptly forgot about it) is reasonable. Once he realized that the incorrect tweet existed, he's been going out of his way to correct it on many different platforms, including putting a new question about it in the latest Sage Advice compendium and doing a whole segment on Dragon Talk about it. If "following your bliss" means ignoring all of his most recent statements and essentially house-ruling that Shield Master just gives you a bonus action shove, more power to you. I just think it's really hard to argue that it's the intent of the feat at this point in time.