Hi!
I can confirm (only from personal experience) that 14393.5 fixed the WiFi problem: In the time I had this version, my Lumia 650 did not have any WiFi droppings. Unfortunately, 14393.67 came soon, and the problem was back.
Today, I reset my phone because some of the Live Tiles were not working anymore, and at least since then (for just a few hours now) WiFi did not drop. Resetting did not cure the Live Tile problem, though - but that's a different story!
Combined with the WiFi loss is a massive battery drain on my phone.
Yes, 14393.67 has the WiFi issue present for sure. As for the tiles I had the same issue (just for the outlook mail and possibly calendar), to only way to fix it is to go back using the WDRT without restoring any backup, once in, erase the FB app (another issue altogether), then windows update it back to 14393.67 and make the store update all apps, finally install all your apps including FB and you are good to go (working tiles and random WiFi drops again yay!).