I forget where, but a while ago someone (I think MikeT) said he was going to monitor one of his young injured players to see if initial development time was lost during an injury, or simply paused. I didn't follow up on that, but thought it was an interesting question. Recently I had a young player go down for 200+ days and sent a ticket to ask about this situation.
The answer (eventually) was that development time is lost.
My suggestion is to change this. A player already takes a ratings hit from the injury itself. There's no problem with that. But, what's the rationale behind having a player lose out on development time? Initial development time isn't restricted by consecutive years, or by a certain age limit; rather it's restricted by the amount of information and experience that exists at a players disposal...which can happen at any point during their career. I can see it being connected to "make-up" rating, but to just be lost is just an oversight of how development plays out in HBD.
From what I remember there was a similar situation in HD years ago, which WIS eventually fixed after much complaining and denial.