I misunderstood... I thought when you said 'you went looking' for your H's online dating profile that you knew for sure he had one. So you were just looking to see if one existed or you know for sure he has one? Sorry, I am unclear.
Assuming, mind reading and speculation is not productive. It doesn't matter if your H knows you are an information vacuum or not. You will drive yourself crazy. Would you want your H to assume you are okay with all of this simply because you have not had an R talk with him? Probably not.
In my own experience and the thousands of situations I have read about on this form, on another forum and in my real life divorce support group often times (not always but it seems to be more often than not) a WAS will call the first few months a trial separation. That way the WAS can say they *did* try and walk away with less guilt. I also think WAS's offer a trial or controlled separation so they LBS does have time to get on the same page.. or that is what the WAS thinks or hopes will happen. WAS have a "fairly tale" like idea of how the divorce proceedings will go.
I guess I don't understand the difference between a trial or "regular" separation. Either way, at the end of the day, the two of you are not together.
If you are not 110% sure he is dating I would leave things as they are. If you find out otherwise then make your decision.
If your friend is reporting back to you what your H said then your friend is involved no matter who initiated it. I know she is your friend but in the long run, talking to friends that have a R with both the LBS and WAS can get very sticky.