It's worth remembering that Conor was only stripped of his FW belt because Cormier hid his injury against Rumble to the last minute and so the UFC was stuck promoting Holloway/Pettis to main event of a PPV. Which required it to be a title fight, yet they already had an interim champ in Jose Aldo. They obviously couldn't have an interim interim champ so it was either strip Conor or strip Aldo.
Conor had the LW belt to fall back on, and Aldo was the recent longtime FW champ anyways so stripping Conor was the lesser of two evils. But it was only done because Cormier hid his injury so long. Otherwise they'd have had more options like moving the event back, having Conor/Aldo defend against Holloway/Pettis (or unify their belts), get a new main event, etc.
We have no idea if Conor ever actually was going to defend against Aldo. That got taken out of his hands when he got stripped to avoid the incredibly bad look of having an interim interim champ.