I actually think this is a bridge too far.
I'd be in favour of somewhere in between the previous position and this one, whereby some trigger - unlocking one or two of the ingredients required for something but not all of them - caused the spell to show up in its stripped-information form as now. So at the beginning there's very little there but quickly it blooms to include more which you can pursue if you so choose.
In fact, I'm still of a mind that the previous position was far better than even that suggestion - since I actually agreed with the assessment that new players wouldn't even know about a given spell until they'd unlocked its ingredients so would never ask, "How do I unlock x?" without extra-game information such as a wiki - which would itself be able to answer the very question it posed.
The reason I feel quite strongly about this is that the similar Monster Hunter mechanic is one of the strongest elements of that game for me; and that's one of my all-time favourite games. The first time you fight a new monster and collect some new resource from it - a horn, tail, hide or whatever - there's a thrill of visiting the smithy to see what new weapons an armour you've unlocked. Immediately you can see all the details of those items so you know whether you want to hunt however countless more of those monsters to build the sets. Or conversely, so that when you come up against another new monster against which you're not currently powerful enough, you can check over all the stuff the smithy will presently make for you and go off to hunt the appropriate monsters to acquire the right element-damage or -protection, etc.
Of course the gating in that game is about which monsters you are currently able to fight (and have fought successfully at least once) which is what triggers new stuff in the smithy. Simply having the common ingredients will not unlock the new equipment, obviously. The monster-specific ingredients are key.
So, after much rambling, TL;DR:
I advocate actually fully unlocking spells in the Grimoire (as previously) as soon as you have unlocked the one most relevant/gated arcane ingredient for that branch. You needn't have unlocked every single ingredient yet - thus it gives you something to aim for, if you want that spell - but there's still the excitement of seeing what you might unlock next without knowing about it beforehand. I'd also put things in the Grimoire with their full stat information from the get-go, since it's impossible to simply plan around "this looks shiny" anyway.
Finally, if something in the Grimoire was revealed on a previous continent, it should be shown thereafter for all continents (I'm not sure if it did that previously) because that's the one genuine in-game case where a user will know what they want from the continent at first but may not remember how to unlock.
