Before Star Trek: Discovery was around, back in 2009, J.J. Abrams set up several mysteries during the first Kelvin Timeline movie. The imaginatively named Star Trek. The most significant one of these for the 'Prime' Star Trek timeline was the Romulan Supernova. But is Star Trek: Discovery Season 5 e...
Even the Romulan-heavy Star Trek: Picard Season 1 avoided addressing or explaining the supernova in any detail.
Explaining? Stars go supernova occasionally, there's your explanation. There doesn't need to be further cause or intervention behind it.
IMO this is a solution (or really several) looking for a problem that just doesn't exist. As it stands and despite fan speculation, Romulus was destroyed by a natural disaster, which is actually something that happens on Earth and in the wider universe.
Not spontaneously, with only a handful of years' notice, they don't.
I'm all for Trek science being a little weird, but it seems very likely that there was some funny business going on for the star to suddenly blow up and threaten the entire galaxy.
The wiggle room within Star Trek is that the Tkon Empire was supposedly wiped out by a supernova despite being a highly advanced civilization, and in "Second Sight" the DS9 crew boosts the top speed of a ship to warp 9.5, which suggests that a supernova can have superliminal consequences.
But there's nothing to suggest the Tkon supernova was a natural phenomenon, and the hijinks they were up to in "Second Sight" certainly wasn't.
Explaining? Stars go supernova occasionally, there’s your explanation. There doesn’t need to be further cause or intervention behind it.
Stars don't just randomly supernova. Stars have extremely predictable lifecycles. It's hard to believe a warp-capable species never made it past a 19th century understanding of how their sun works, especially given how fundamental the underlying principles are to our own ability to observe and understand the universe.
It's a plot hole in ST '09, though I agree that maybe it is best ignored unless they can come up with a truly compelling explanation.