Aaron Hicks is a weird case because, on the surface, he is a guy that appears to have been reborn since joining the Orioles after his release from the Yankees. After several seasons where he struggled to hit at all, Hicks slashed .275/.381/.425 in 65 games with the Orioles. That is legitimate production and the front office deserves kudos for picking him up off the scrap heap.
However, there is a lot to consider here when it comes to trying to keep him. One, other teams are also going to notice that the soon-to-be free agent Hicks' good work as well which is going to make his price tag jump considerably especially when you factor in the fact that he plays a competent center field.
The Orioles also have some really good outfielders coming up from the minor leagues. Colton Cowser, Heston Kjerstad, Dylan Beavers, and Enrique Bradfield Jr. all appear to be very legit outfield prospects and at least some of these guys are going to need playing time sooner rather than later and all of them have more upside than Hicks brings to the table.
When you factor in Hicks' lack of an offensive track record in recent years, the potential cost associated with keeping him, and the internal options that Baltimore is likely to have at their disposal here very soon, it just doesn't make a ton of sense to keep him. Now if he wants to stay in Baltimore on a cheapish, short-term deal...well, that is a different story entirely.