I think the potential downsides or unknowns have little risk of happening. The only upside is the potential of having an existing card is if the acquisition happens and the card is closed to new applicants (like the Arrival+). In that case, you wouldn't be worrying about future SUBs with that card. If you value the opportunity for a future SUB a year from now, I'd close the card. To give you some reassurance, I closed my AAdvantage Aviator card in November 2022, applied for a new one in October 2023*, and had no issues receiving the SUB for the new card. Granted, the card I closed in November 2022 had a longer history than two months, but I had no issues with approval of the new card.

(*My reasons for opening the card again were not for churning but rather due to the fact that AAdvantage Hotels changed to giving a Loyalty Points bonus if one is a cardholder of any AAdvantage branded credit card. I recognize that Barclays would have no knowledge or consideration of my underlying reason for applying for the exact same card product one year later, however.)