Are we reading the same thing?
The whole point of the dragons disappearing (hiding in the dragon slayer) was so that they WONT turn into dragons

That it was, yet here we are, with a dragon slayer turned dragon who can turn back to human form at will. Maybe he knows something Igneel didn't

The point of the dragons hiding inside was to suppress the change...

Are we fucken reading the same thing?
No one stated that the dragonfication is a permanent thing.

If the dragon form was something temporary that could be dismissed at will, I seriously doubt these dragons would have all sacrificed their lives just to stop it,never ever assisting their adoptive sons when they needed it unless they thought it would be permanent.

I'm sure there's something at play here beyond what the dragons know about. Sure, they said all this, but I'm willing to bet fg there's something really game changing they're not getting.

Or changing to a dragon makes them lose their senses, and after 400+ years, acnolgia learns to change back to human form by gaining his sense back
I forgot since this is so long ago but didnt the council send acnolgia to their shit
maybe thats why he gained his control back

Well, didnt they said somewhere in the Eclipse arc that acnologia is a former king(dragonslayer) that feasted with dragon blood?And because of that he gained the abilitty to turn into a dragon? I mean no dragon slayer we know, killed a dragon till now, most of them are just enhanced

I wonder whos the 7th guild master, Laxus?

No, they said he killed enough dragons that spilled their blood on him that he changed personality and forgot his goal or something along those lines.
AKA he used his dragon slayer powers so much he turned.

he looked quite sane to me...

I approve, Ezra is a good choice for the new guild master