I like Keith Lee a lot & think he could be a big star if pushed correctly, but he's still just an upper midcarder in what is basically WWE's minor leagues. He has minimal main roster exposure.
Having Lee win the Rumble would be like a baseball manager deciding in September that one of your best minor league pitchers is going to start game one of the World Series. Does that make sense?
I don't think anyone was seriously suggesting that Keith Lee should win the Rumble. However, eliminating Brock Lesnar and getting the match at Wrestlemania? Definitely a play they could have made.