you still restore glycogen stores when short on carbs. you simply can’t expect any supercompensation which is one of the key adaptions performance oriented athletes are seeking.
Even when on a low carb diet with 100-150g/day you see this restoration. However, you will have a higher storage of intramuscular fat, which is a valuable engery source as well.
Different when you’re on keto. There it is suggested that glycogen stores are normalized due to enhanced gluconeogenesis. Furthermore, blood glucose can be synthesised via a variety of other substrates ( https://www.physiology.org/doi/abs/10.1152/ajpendo.00397.2012 ). Therefore, highly fat adapted elite ultraendurance runners to not differ that much w/r to glycogen storage:
Volek et al 2016