I think the short answer is: It depends

You need to make sure it's the same person posting and it's not a stolen account first (since a few years of inactivity is a lot).

Another point is that a lot of people got a bit discouraged by the cryptocurrency evolution this past year so, this can be a reason for inactivity.

Some were just busy with other projects (myself included).

If you think of it, even a very active poster can bail on you when he loses interest so, it's kind of the same thing.