I don't think this is a bad attitude to approach modern Trek with. Discovery works on certain basic building blocks for its season-long plotlines, too - but twice or thrice now, the writers have had to reinvent themselves, abandoning the original intent for the blocks and introducing an all-new intent. It's not difficult to do: the square pegs are still square, they're just painted differently. But the audience is kept on their toes, trying to figure out what sort of a structure will emerge... And which previously important blocks will be abandoned in the corner, to be replaced by ones out of the left field. (And mixing of metaphors is just a nice metaphor for what's going on there, thank you.)
The supernova thing in PIC really is the best of all worlds. It doesn't contradict the 2009 movie outright - it actually explains how Spock could "be en route" during the kaboom, rather than carefully prepositioned with a safety margin of several months or years (kaboom can't be predicted down to the minute, and it happening right next to Romulus requires a fast ship and a big helping of luck, only one of which Spock has). It also nicely shows that there might be multiple rescue plans in motion, some less successful than others. And a forewarning of less than a decade is ideal: there's disbelief since all of a sudden a star that shouldn't be capable of exploding shows signs of intending to, there's too little time for anybody to wrap their minds around that, but enough time for conspiracy theories to emerge.
Best of all, something so huge serves as mere background for the actual plot here... So even the three key building blocks above can be juggled, perhaps dropped and slightly deformed, and reassembled in different ways, and overall the writers can still say "it always happened that way, you just misunderstood the general gist while inventing detail that wasn't really there". We don't have a detailed timeline, there's no data on who noticed the star was going to blow, how and when, no careful list of what happened before and after the key events known so far. Plenty of room for all-new key elements to be introduced there, I mean. This would be more difficult were the supernova at the sharp focus of the show.
Timo Saloniemi