I don’t think that criticizing Rogue One for fan service is fair. It’s not as if it could get away without using X-Wings and TIE Fighters. It was set during that time period, so of course we’d see some familiar characters and designs. The only cameo I think was a bit too much was the cantina guys.
And I think the Han Solo movie will be the same, even though I think it might explore some different aspects of the galaxy regarding bounty hunters, gamblers and such things, with the Galactic Civil War not even being a present element in the movie, and the only familiar things be the characters and the Falcon.