I think it's too bad in a way, it's the last thing the country needs, more shenanigans like this. And I don't think it's very clear that the new leader will have any better ideas.
There is something really wrong when neither of the major parties can keep a PM in harness. And there wasn't necessarily anything deeply wrong with them, Boris's problem was lack of self-disapline mainly and a kind of laziness, but Sunak would I think have done a good job.
I'd be very surprised if they called a GE after though. The might go a little earlier than they would otherwise, but whoever is the new leader will want a bit of time to consolidate and then will wait until things look to be about as good as they are likely to get. They will want to set up the conditions to give themselves the best chance.
Ultimately unless they start to really look at the electorate with some level of clarity, they are not going to be able to make it work. it's the same as the Democrats in the US at the moment, they are so unable to honestly look at the public that they are incapable of maintaining public trust or messaging in a way thatis effective.