Hey nostriches, anybody here who understands coinjoins background in details?

I have a question concerning address re-use.

1) Please have a look at this video and please comment those who understand that problematic.

Was this Wasabi 1.0 or Wabisabi 2.0?

2) Is it technically possible that address reuse can happen?

3) Please, only constructive information, no beef between 2 sides. I don't seek for a information what is better...

Thank you