Aceromantic is a term on the asexual spectrum what stands for a person what one finds that the easiest, best, or most convenient way to describe one’s romantic orientation is by tying it to one’s asexual identity. This does not mean that the person believes that asexual and aromantic are the same, it is just that they associate their asexual orientation with being also aromantic.
The way this could work is if there are not many educated people to know about aromanticism and the AroAce person says they are asexual, reffering to their AroAce identity. Similar to being a non-SAM asexual person.