Assertions that Twitter/X was surely going to shut down after the Elon Musk acquisition were wishful thinking on the part of two groups of people:

1) political progressives who liked the way the pre-Elon-Musk management of Twitter engaged in political censorship on the platform (i.e. anyone using the term "nazi" with respect to Twitter or Musk)

2) software engineers who saw a bloated software company summarily fire a bunch of software engineers who the new leadership thought were mostly doing unimportant work, and really wanted it to be true that this was going to tank the company, because it was bad for their job security if it turned out that Twitter didn't actually need that many software engineers after all.