Hey guys, I’m looking into this now and will get back to you as soon as I have more info to share.
My current understanding is that systems that had ice should all still have ice spawns but I need to clarify what exactly it was that was reduced. I know the ‘The spawn probability of all Ice Sites has been reduced’ from the patch notes is a bit confusing when they were previously guaranteed to come back on that 4 hour timer after being mined out.
Update: Okay so I’ve clarified what’s happening here. As you’re aware, previously ice belts were guaranteed to respawn in system 4 hours from when they were mined out. This respawn chance is no longer 100% guaranteed and so it is possible for belts to not come back exactly 4 hours later - it may take them some time longer to re-appear. The number of belts in a system hasn’t actually been changed and each will be rolling for its own chance to respawn if they’re all mined out. This will mean there will likely be less belts alive at any given time because they simply can take longer to come back.
Please see Ice Mining for a more recent update.