Yeah, I think you could be right there, actually. My instinct on this from the start is that it would prevent the grieving process from completing properly. There's a thing called the gestalt cycle of experience where there's a normal, natural mechanism for a person going through a new experience, whether it's good and bad, and a lot of unhealthy behaviour patterns stem from a part of that cycle being interrupted - you need to go through the cycle for everything that happens in your life, reaching closure so that you're ready for the next experience to begin (most basic explanation), and when that doesn't happen properly, it creates unhealthy patterns that influence everything that happens after that.
Now I suppose, theoretically, there's a possibility that being able to talk to an AI replication of a loved one might give someone a chance to say things they couldn't say before the person died, which could aid in gaining closure... but we already have methods for doing that, like talking to a photo of them or to their grave, or writing them a letter, etc. Because the AI still creates the sense of the person still being "there", it seems more likely to prevent closure - because that concrete ending is blurred.
Also, your username seems really fitting for this conversation. :)