They always just say, use obs, lol. Nobody cares if you say last anymore.
Also, when they obs, they should be ally-able so you don't keep attacking their buildings every time you want to attack something/someone else. Before, if they say last, you can use that building for your advantage because you have allied them. Even if they didn't say last and they have buildings, you can use multiple ones too.
Now, my units will always attack that building/s if they obs too early. (so many obs too early and don't understand why it's dumb, I don't get it)