The Umpires Association will definitely make a fuss about this even though it is ultimately better for them. No one will be able to question the result of a game due to balls and strikes anymore. Didn't think the calls were right, why didn't you challenge. Mismanaged your challenges and didn't have any left, too bad, that's the coaches fault. 

But they will likely see it as a slippery slope to full robot umpiring. 

grayruby

I don't think it's gonna change anything for umpires, albeit they'll be assisted. As I said it's used in Cricket for a long time and no umpire has lost his job because of this. The technology will only be used in decisions where umpires can often go wrong or often confused. 

Coinsreporter

Stacker_Sports

MLB to test robot umpires as part of challenge system at next Spring training

>He also said that there are ongoing conversations between the MLB and the Umpires Association in relation to the new technology, with their collective bargaining agreement set to expire on December 1 this year,

I could see the umpires striking again over this.