Well, if I had to say something;
One would be it feels like forever until the new videos series come out after they are announced. Though, I do understand why. It takes a long time from having the idea and deciding to do it to actually producing it. But, it still would be nice to get the stuff sooner after it's announced.
Only other thing would be that sometimes it feels like we go through lengths of times without any new content. Again, this is understandable, but it no less something I dislike.
I just have to say this as well, I saw a few say a schedule would be great for your channel. I highly disagree, schedules get rid the fun of checking your channel everyday not always knowing what you'll find. Some minecraft youtubers I like scheduled there channels this year, and it actually made me lose a lot of interest in their channels. There's just something about not knowing what you will find that makes channels fun to follow.