That is really on point, thanks!
ps. watched the presentation - the idea here is that static type checking can eliminate entire category of possibile bugs which are impossible to be eliminated by test - for example enforce variables to be of specific type only.
It doesn't work that well where in the most bug prone places typings are made optional.
Type safety and tests are completely orthogonal issues. Gary Bernhardt explains this really well:
https://www.destroyallsoftware.com/talks/ideology