The Griffon is not hauldown capable without major mods to the airframe. In any case, the JSS won't have a hauldown system any way (just like our current AORs).
It is theoretically possible for Griffons to operate from any of our ships now. The problems are (in no particular order):
1. A rotor head that doesn't easily fold (if at all- can't remember- you may have to remove the baldes to get them in the hanger.)
2. Skids. A dangerous thing on ships. You have to a cart to move the helo; you have to put rubber on the skids to help dampen vibration and you have to be extremely careful to avoid "deck resonance" which can quickly lead to the helo overturning on deck.
3. Aircrew training. Landing-on/Launching from a ship is tougher than it looks. Untrained pilots tend to "follow" the motion of the ship and not wait for the ship's steady period. Mess that up and you go swimming (if you are lucky...). They also don't know navy flight procedures, which is a whole other language that tac hel guys aren't taught.
4. Technician Training and Aircrew training (Pt 2). Operating from a ship means, like it or not, being part of the ship's damage control organization, which means a couple of weeks of initial trg plus work-ups.
5. The Griffon is not especially "Sea-proofed", which means that corrision control procedures would have to be developed on the fly.
None of the above by itself is a show stopper (except maybe the rotorhead part) and can all be fixed with training, but the skills are perishable.
The training issues can be dealt with of course, but at what cost?
I think that is good to begin to have the debate about what, exactly, we intend to fly off of the JSS, apart from Cyclones.
I once, tongue-in-cheek, suggested that we keep a bunch of Sea Kings as troop lifters (gutted interiors, Self-Defence suites, door guns front and back) but was told to STFU and get back in my box.
Cheers