You can put ability words in italics by surrounding them with single asterisks or underscores. Brave decision to bring back Threshold somewhere other than 7, but I can see why.

WHich bit do you think should be in italics? Why "brave"? Is there some reason it's a bad idea that I don't realise?

I think "Threshold" would be in italics - see the Time Spiral reprint of Mystic Enforcer.

As for Threshold places other than 7... It depends how much you're doing it. If it's just on 5 rares and 5 uncommons, say, then it's not going to be much of an issue. But if it were on a bunch of cards including several commons, the varying numbers would make bookkeeping through the course of the game an immense pain, moreso than just when it was just Threshold 7.

Hmm, I was looking at the originals which aren't in italics as well as other keywords that aren't. I don't think the bookkeeping would be too onerous, I'm certainly not worried about it. Just a matter of knowing the number of cards in each graveyard, which is fairly easy to see at any time, anyway. There are plenty of harder things to remember in this game!

The originals aren't, indeed, but that's because it was a keyword mechanic. With the Time Spiral Oracle update, Threshold got errataed to be an ability word like Hellbent or Metalcraft, which are printed in italics.

Aha, didn't realise the distinction. I'll update any affected cards sometime...

Inspecting the wording in more detail, it should say "you may have ~ deal 1 damage" rather than "you may deal 1 damage". Also, if Wizards were printing this kind of effect on a new card, they'd say "Whenever..., if there are three or more cards in your graveyard, you may...". However, in Time Spiral and thus I'm guessing Time Reversal, they deliberately chose to match the odd-sounding Oracle wording of older cards, so the "As long as..., ~ has "..."" is correct :)