TM DB/Hu Dragonite?

TMs wont give DM sadly.

Go for DB/O its not obtainable anymore and offers lightly better dodging potential. The only drawback is DPS is slightly lower then DT/O

You are right if you can max 6 of flying type of Rayquazas without any difficulties.

The only argument I can think of for DB/H is that it is the most dodge friendly move set. AA is a bit faster, but you have to expose the dragonite for more 2+ second windows to do the same damage. Dodging isn't really important in the current meta, but the meta can change.

I recently TM’ed my hurricane Dragonite because I never used it and wanted another DT/O for my RayQ team.

The only thing I don't like about TM to Outrage is the damn autoselector doesn't like 2 bar moves.

It would give Hurricane Dragonites as neutral options for bosses, but not Outrage ones.

Other than that flaw, I'd go for Outrage

I changed my remaining hurricane to outrage, got it on first try. Rayquaza's outrage is actually dwindling my revives, need to raid with mid-big groups again

It all depends upon if you have enough rare candy to develop Rayquaza. For me it's easy. I only participate in a few raid each week which makes rare candy really rare. Thus, to develop a Rayquaza is out of the question. Instead, I will put my rare candy into power up on Groudon, Kyogre and Mewtwo.

Rayquaza is only marginally better than Dragonite and development of a Dragonite do not cost me rare candy. Thus I will keep my Dragonite with Hurricane.

You might regret TM'ing it if hurricane becomes legacy and Dragonite gets a flying quick move.