It made perfect sense to cut it there. It was a cliffhanger with Paul finishing up.

Secondly, you even seemed to say so yourself that John was written more isolated from the synoptics, so if they were trying to “censor” out when making stuff up, why would he include her in his gospel in the first place?

Because there is no “they”. It was separate groups putting out works.

Lastly, that’s assuming Marcan priority, which generally tries to presuppose that Matthew wasn’t an eyewitness account in the first place

Which is a valid assumption since Matthew was not an eyewitness and Matthew copied Mark word for word at places. There is no presupposing here. Whomever wrote those two books were liars writing propaganda.

The early church clearly records Matthew as being written first and Matthew being written by Matthew

Genetic fallacy, sub-type argument from authority, logical fallacy. Something is true because it happened not because someone said it happened.

keep in mind that the Gospels were widely circulated by then and they had already rejected forgeries under names such as Peter)

Irrelevant. Being right about one thing doesn’t mean being right about everything.

and Marcan priority was only hypothesised in the late 18th century,

And so was the germ theory of disease which I sincerely hope you buy into.

yet is still quite debated.

The existence of an argument doesn’t mean both sides are equally likely to be true.

Athiestic Bible scholars like it because it is useful for them to explain away the Bible.

Circumstantial ad homunium attack. Another logical fallacy. 4th by my count.

I suggest you read up on logic a bit before going further.