For the most part any of this later technology really doesn't want to be in the main set. But we can posit a spin-off game that includes whatever it is, and then say yes, certain cards would be different. We can also imagine that some particular card could have not happened on cue, and later appeared in whatever set. And of course any edge cases are moot, the cards want to be the best versions of themselves possible and even things like "you can Crown a Horn of Plenty" just wouldn't matter to me.
Night: Obv. Horn of Plenty would be a Night card, the example I have endlessly given already, and sure maybe Scheme.
Exchange: I think of this as, well not exactly a failed experiment, but something that was better constrained to the Travellers. I think it confuses people and the move is not to use it. Trader, as I've said in the past, either it should not have the reaction, or the reaction should let you trash a when-gained non-silver card to gain a silver. Of course a spin-off could have exchange but not when-gain, or could just really require that people learn all about exchanging day one, as a basic part of the rules.
Debt: Yes this is better-to-use than the -$1 token, though Ball would be $5 and D, not $4. I don't imagine Debt would find a lot of other use; those 8D cards were tricky. However the Engineer trick could come in handy elsewhere (since it costs Debt, it can't gain itself).
VP tokens: Well you don't really get anything changing Distant Lands, I mean it's one thing or another. You might be able to get a little use of VP tokens though, other than completely new cards; Harem for example could be an Event with "+2 VP, gain a Silver."
Events: Yes some one-shots and when-gain-style one-shots could be Events instead. And a few other cards, like Harem. I don't think Events would eliminate either one-shots or when-gain cards, but there would be fewer of them. It's tricky because, when you convert the card to an Event, you lose some specific fun that you notice that you're losing. I enjoyed using TFB cards on the thing that became Banquet, for example. But this is always up against "but the Event just takes one slot in the set, and the kingdom card takes eleven."
I think Events are easily the winner, in terms of what you get out of having them.