Tough luck Wigan. Why should other L1 teams like ourselves who have got games on even with Covid stretching our squad to breaking point suffer because they haven't and because they've had Cup success. They could have always put out weak teams in the Cup and still can if fixture backlog is a potential problem for them. I remember us seeming to play Tuesday/Saturday for January/February when doing well in Cups a few seasons a go and I don't remember any suggestion of the season being extended for player safety. As I say tough luck Wigan, use your squad, so I have no sympathy as fixture backlogs have happened for a couple of teams across the leagues every season since I can remember (bar the cut short season) and Covid isn't a justification.
Also, I've played in local teams where we were playing Tuesday, Wednesday, Thursday and Saturday for 2 or 3 weeks and reasonable standard non league teams higher up have had similar schedules for longer.