I don't want further explanations to prevent other conflict.
By dodging a question like that, it implies there wasn't really a valid reason for giving those statements and that complicates things further!
I would say that the decision to close the campaign is probably not completely founded.
If Gianluca95 didn't halt the campaign, sooner or later it would've led to some conversions and that's where it gets tricky.
Are they thinking the private key will be exposed?
If so they can move some funds from address a to address b. However signing a message is completely safe.
My guess: they have no money so they can't sign anything and made up a lousy excuse.
In addition to LoyceV's comment, this is the second time I'm seeing someone making such comments
[e.g. signing isn't safe] in the past month or two
[I had no luck in finding the other user], so either they're connected or they're misinformed
[most likely it's what LoyceV said earlier].