Yes, they are about League average for that period. Scoring has gone up, dude. Anyway, who cares about a few degrees of save percentage? Wins are what matter. The Leafs, just like the Oilers, are an offensively-tilted club who, despite considerable talent, give up a lot of scoring chances. If a goalie's (long-term) stats are "average" on those clubs, then the goalie is probably slightly above-average in actual ability.
Here's something Leafs' fan may not be aware of since 1967: You don't win the Stanley Cup with save percentage. You win with wins. Campbell is probably the winningest goalie in the NHL (in win percentage) the past two seasons combined. The Leafs won, at a fabulous rate, when he was in net. He was the least of the club's problems.
How about we look at a larger sample than three months of last season? Here's the save percentages of goalies the past two seasons (min. 40 appearances):
1. Shesterkin .928
2. Sorokin .923
3. Saros .921
4. Varlamov .920
5. Vasilevsky .920
6. Swayman .920
7. Smith .919
8. Kuemper .917
9. Ullmark .917
10. Campbell .916
11. Forsberg .916
12. Fleury .915
13. Jarry .915
14. Markstrom .915
15. Demko .915
There are 53 goalies on this list, and Campbell ranks 10th. That's very good, especially since (as noted) Toronto are an offence-heavy team. And that's including this mythical "horrible period" he had last season.
Unfortunately, this list also makes Mike Smith look good on account of his excellent 2021 season. But I think we all know that Mike Smith is awful.
What the Oilers desperately need is a new, functional goalie tandem. I personally am pleased going into the season with Campbell and Skinner. The reigns are there for either one to grab, but I think they're going to need both of them playing consistent, decent hockey, without Mike Smith's tendencies to roam and give up goals while staring down and blaming his teammates.
Like the Leafs, the Oilers simply need League-average goaltending, but from now on without any drama, please.