Considering development time, server setup, testing time, etc… They probably did. It probably took several months to develop, deploy, integrate with the rest of their systems, and test. And then it’s simply a matter of waiting on Musk to do something stupid before they announce the launch, so all the freshly spurned users are happy to switch.

Threads still doesn't have #hashtag searching IIRC. It's missing a huge number of features. It's clear that they only came out as early as they did because they saw an opportunity to eat Twitter's lunch.

They really needed a few more months of dev time.