Widow mine nerf seems a good idea since now protoss players will be able to clean them easier in the early game and prevents the game from ending in less than 5 minutes just because the terran player burrowed two widow mines in a mineral line.
This tweak has been made to address early WM harass in the TvP matchup, but it's also a nerf to TvZ bio, especially against LBM (and Hydra Bane). TvZ is probably the most balanced matchup and this WM nerf could disrupt the game a little bit.
This is my suggestion: Drilling Claws upgrade now brings back cloak to Widow Mines after they shoot (current version of the unit) in addition to the fast burrow.
This upgrade is only researched in TvZ when Terran is at least on 3 bases and he's facing LBM (and sometimes against Hydra Bane). The upgrade is never used in TvP besides mech players yet it gets researched in the mid-late game, so it shouldn't affect early game harass and game ending situations.
With this little change, protoss players will still be able to defend early WM drops and the WM nerf will not affect the TvZ matchup that much in favor of zerg.
Thanks for reading!