@OldPlayer covered that.
The answer here is found in your question. Slade was subbed in to play Quarterback. I have a hard time seeing how something so simple can be so convoluted with these examples you're trying to use.
Nothing convoluted about it, it's quite simple.
In that same game, you're OK with a WR being subbed in to play QB (with another QB on the field, no less), but not OK with a punter being subbed in to play WR. The similarities are obvious in that both are going in to play positions they don't primarily play, but one plays for the team you cheer for and the other doesn't.
I completely understand if you'd want to call penalties on both parties, but you don't. You're asking the officials to sort through the "intent" of one team, but not the other. (The fact that Mac Jones stayed on the field when Bolden played QB is an obvious signal to the manner in how that "substitution process" was being used... But I digress).
-------------------------------------------------------------------------------------------------------------------
And on a completely different point - Auburn never ran the play. The Punter was clearly motioning into the backfield with 10 seconds on the play clock. The penalty was called on Alabama before they ever ran a play, which quite easily could have been a punt. Now - I'll be the first to admit that I don't know how the "too many men on the field" rule is supposed to be officiated on the defense. Was it supposed to be called that early? Or was it supposed to be called after the play had started, to give the 'D' more time to sub a man off? If it was called incorrectly than there is more of a beef... If it wasn't, then you can't flag Auburn for "confusing" the defense, when you don't know what the play is. At least not objectively.