The meteorites may have been cold for a long time, but that doesn't mean anything. We have no idea how long either meteorite took to reach earth in the first place.

Its this sort of broad statement, that mars has been frozen for 4-1/2 billion years, that gets a bit of coverage, but the assumptions are just that...assumptions.

IF the rock hasn't been floating through the solar system for a few billion years, and IF their estimations of the original argon level that should remain are somewhere in the ballpark, and IF the meteorite did originate from the surface of mars, then MAYBE the surface of Mars (from the point of origin!) has been frozen for the guesstimated time. So many IFs.

The bottom line is the paper is inconclusive and thinly concealed self-promotion.

Yes, there are wet mars advocates and now there are frozen mars advocates. We don't have anywhere near enough data to say either way for certain. Those meteorites are a dead end in terms of trying to understand mars, whether it regards past life or the temperature mars has maintained for the past 4-1/2 billion years.

Panspermia has (unintentionally?) been given a shot in the arm as well with this paper. That opens up the door to all sorts of other theories and speculation and the paper will be used to justify why we should not bring back mars rocks or why AIDS came from space.