Well this problem is not only limited to the Italian Ho-Oh.
The German and French ones are also affected. The full German OT "DUELLBERG", the full French OT is "MT BATAILL".
I don't have any CK3 file of them unfortunately, but I found several videos showing people catching the Ho-Oh with the long OT. Like these:
German: https://youtu.be/xNQvE1vBUnk?t=1541
French: https://youtu.be/12qmSBy43g8?t=15411
Regular Pokemon shouldn't have an OT with more than 7 characters though.