Once a week is perfect for new channels regardless of channel type. There's another myth that gets posted on here saying the gaming channels should post daily if they want to grow. That's not true at all. As though gaming videos are somehow different and have a different algorithm ?!! When you ask them why they think that, their reply is "Erm, because that's what other gaming channels do." - Well that's not a reason at all, that's just being a sheep without thinking about it logically. They see pewdiepie posting daily and they think that's what will work. I've been on YTtalk for 3 years and in that time, I've seen thousands of gaming channels come and go. About 5 of them were growing organically and none of them posted daily when they started.
The reason why posting daily will hinder a new channel's is due to where it'll be getting most of its traffic from: A new channel by its very nature won't be getting much traffic from SEO or suggested videos because that takes time. In the beginning, quite a significant part of a new channel's trafic comes from people just landing on the channel's home page because the owner has been pimping the link or people have clicked on a comment made on someone else's video and they too land on the channel home page. Then what happens is that they'll click on the most recent video. If the channel owner, uploads weekly then that means that he'll get a week's worth of views on one video, which could be quite a few and that'll help the algorithm to build up significant data about audience retention. Whereas, the channel owner who uploads daily is only going to get 1 day's worth of views before the video moves down the pile. The total number of views across the channel would be the same but 7 videos getting 50 views each (uploading daily) is worse than 1 video getting 350 views (uploading weekly) because the algo doesn't have enough data to work with per video.