The removal of python2-* subpackages in staging is done and now it is included in TW.
Now this of course still broke some packages  but overall it is going smoothly (less than 10% of py packages are now unresolvable or failed).
If you are maintainer of stuff thats suddenly not building you have couple of scenarios:
1) optional python2 dependency a) if you wanna backport the package to Leap15 then you can use %bcond_without python2 to condition the parts.
b) or just remove all the python2 deps and code and make the package TW only if you desire so.
2) hard python2 dependency
Tough luck, unless upstream switched to python3 the package will probably depart from the Tumbleweed.
We will be fixing the unresolvables for the important stuff and what we directly control but for the leaf packages we will leave it up to you. Feel free to poke on #opensuse-python and ask if you are not sure on how something should be done.