Josephus and other contemporaries on Jesus

[JairCrawford]

One issue with dating Mark as late as 130 A.D.
is that we have a fragment of John from c. 125-175 A.D. which could cause some overlap in the dating.

Correct. There have been no discoveries of 1st century manuscripts. In fact P-52 is, iirc, the oldest known manuscript we have. I know its 2nd century. The earliest date people initially gave it was 100 AD but that's been re-evaluated recently to 125-175 AD, which could put it closer to the 3rd century. I'm not contesting that point.

However; this does not mean that P-52 is the original of John.

Although Rylands P52 is generally accepted as the earliest extant record of a canonical New Testament text, the dating of the papyrus is by no means the subject of consensus among scholars. The original editor proposed a date range of 100-150 CE; while a recent exercise by Pasquale Orsini and Willy Clarysse, aiming to generate consistent revised date estimates for all New Testament papyri written before the mid-fourth century, has proposed a date for P52 of 125-175 CE. But a few scholars say that considering the difficulty of fixing the date of a fragment based solely on paleographic evidence allows the possibility of dates outside these range estimates, such that "any serious consideration of the window of possible dates for P52 must include dates in the later second and early third centuries."

Wikipedia || Rylands Library Papyrus P52

Your fragment might conflict with a late dating of Mark if we had a solid date for the fragment and that date actually conflicted with dating Mark to 130 AD. Unfortunately, you really don't have either. So what you have is a speculation that if you take the lowest of a range of possible dates for P52, and consider that range itself reliable, then we have a conflict.

Regardless, I don't know that many argue for that late a date for Mark. Were you replying to some specific claim?

I don't think it was so much a claim as it was interesting speculation (correct me if I'm wrong), but Minimalist pointed out that a Roman emperor ordered the ruins to be destroyed and a city built on it in 130 AD and that it could potentially correspond to Mark's "no stone left unturned" prophecy.