It flew a more northerly path due to a big storm over it’s usual route. It flew 2 “air highways” farther north to avoid the storm. One of the news networks overlaid the flight path with the weather radar screen, which clearly showed the storm. It was not flying over restricted airspace.
I don’t think the issue is whether the airspace was totally restricted at all altitudes, rather the point is that prudent airlines had already taken deliberate steps to reroute flights away from an active war zone where combatant aircraft had recently been shot down at lower altitudes. It has been reported that there was already a 32,000 foot minimum, which if true establishes that civil aviation did perceive a threat from the active war zone.