This Durant situation changes a lot for us. While he was still a long shot, he still represented the most attainable free agent on the market. That seems to be off the table now.
Kawhi remains a mystery as he could stay in Toronto, bolt to the seemingly preferred Clippers or surprise going to Brooklyn or New York. You can get him? YOU DO and then think of another veteran piece to surround him with, in my case I would get Thompson. If you land them both, you COULD consider a trade for AD, although to be honest, I'd rather balance those two stars with young pieces like the ones we have.
Now, if you can't get Kawhi, why make any move at all for AD? You would gut your team from all assets just to get star that while a top talent, is still an injury concern and you would still need to find another star to justify the move.
If KD is off the table and Kawhi doesn't sign here, continue with the slow rebuild. Draft Barrett, do your best in the second round, purchasing picks market and the undrafted market, and go from there. If you can't land the free agent top stars to justify a move for the now, keep moving towards the future.