Honestly, I think that it is a great move and I explain why:
It's Adamek's 4th fight in 12 months, that's a LOT. It would be a bit bold to put him against a top contender with a 4th fight in less than a year, especially because he did climb the rungs pretty well lately. Secondly, this is a good little test for Adamek against the huge guys, especially if he seeks to fight one of the K eventually. So all in all: 1) it keeps him active without burning him, 2) allow him to test the big guys 3) get him and Main Event another pay check in the meantime.
For these reasons I think it is very good, we all know Grant is nowhere close of somebody impressive but in the circumstances, it is a really good overall option.