Did they reveal the extent of the cuts? No, not in the slightest. There's no excuse for not being transparent in the scope of the cuts. They didn't have to give a full list of every Pokemon in the game, but they easily could have revealed generally the total count of Pokemon included (e.g. "Over X Pokemon to catch!").They announced it pretty early to be fair.
Typically Pokemon games get announced earlier in the year and dip until the Summer and get a big blowout and afterwards show off new stuff every couple weeks up until release.. The Pokemon cuts were something they talked about among all the other revealed features at E3 and was done before they started their prerelease.