Though, it might take longer to train them to spot every place where they could/should be using some stricter version of the defaults. That's the problem with opt-in safety.
On the other hand, there are languages that make thread-safety bugs much less likely. Some day those ecosystems will catch up to the languages that have been around "forever" and we'll get our cake and eat it, too.
There really aren't that many places to remember, and there is copious amounts of developer tooling available to identify, and in some cases even fix the issues automatically.
I don't recall ever seeing any kind of dev tooling that can just automatically fix thread safety issues.
Though, it might take longer to train them to spot every place where they could/should be using some stricter version of the defaults. That's the problem with opt-in safety.
On the other hand, there are languages that make thread-safety bugs much less likely. Some day those ecosystems will catch up to the languages that have been around "forever" and we'll get our cake and eat it, too.