mmWave will make a big difference for the likes of stadiums and theaters. Places with huge crowds. A feature of the high frequency is it doesn't travel far which limits cross talk and allows you to pack in more antennas to serve more people.
How often Telecoms will want to deploy it is a different matter. My guess is you'll see it go up most often in places where companies want to optimize customer experiences. Likely as a partnership with the various telcos. For example, I could see the likes of Disney deploying it across disneyworld and disneyland.