2024 GE will be about immigration
In part, yes, but I would suggest that will really just be a headline feature of a wider "culture war" approach. It's already well underway and internal Government memos prove this is absolutely the intention of the Tories.
It's entirely Trumpian. They have no interest in governing the UK for the whole, so all they need to to is convince enough of "us" that everyone else is a problem, and bob's your uncle, another Government with 30-34% of the vote thanks to the bonkers FPTP system, which, of course, they perpetually tinker with in order to favour themselves even more.
As you've pointed out, we've seen this already with Leave/Remain, with 'Remoaners' still being blamed for the predictable, and utterly abject failure of Brexit three and a half years after the fact, a Brexit that Leave has had complete control over for the duration.
So yes, it'll be Mail/Express/Telegraph-driven horseshit, spoon-fed to the gullible, victimising and blaming anyone and everything, immigrants, 'woke', trans, Labour, lefties, ethnic minorities, 'separatists', lawyers, welfare claimants (but not those on a State Pension of course), the EU, strikers and unions, Biden, you name it, absolutely everyone but the criminal cartel who have actually been running the UK into the ground for the past 5 years and their pals and benefactors siphoning off billions in profit and driving the cost of greed crisis, and sure enough, there will be plenty of Tory MP's returned yet again.
In the UK there are plenty enough racists, xenophobes, morons, and wilfully ignorant people who will not entertain the thought that their own prejudices and misconceptions might be the real problem, to ensure the return of this utterly contemptible government. The outcome of the Brexit referendum and the fact that Boris Johnson was ever considered a fit and proper person to lead a political party, never mind a country, are proof enough of that.