I don't think so. I've tried a few last connection dates and they're all over 6 months in the past. Odds are they're burner numbers based on that alone. For ex

I don't think so. I've tried a few last connection dates and they're all over 6 months in the past. Odds are they're burner numbers based on that alone. For example, last number last connected on Sep 13, 2020 (they're just dates, no time info stored), while the account was created on July 7th, 2020 at 16:15:37. Knowing the number's without Internet access for over half a year, person in question is probably unable to compare the creation date and time to the SMS received from Signal.