I think the Picard Series will be a good gauge for how far up CBS All Access Trek can go. It would draw more people than the Pike Show or Discovery. That's fine with me (I'll get into why two paragraphs down). My friends grew up with TNG. That's their Star Trek. I was the oddball, being the TOS fan. A lot of them are looking forward to the Picard Series.
They wouldn't really care about Pike. Other than "I remember Pike from the Abrams Movies!" To them, those films are either "JJ Trek" or they think of them as comic book movies. "I went to see X-Men!" "I went to see Iron Man!" "I went to see Star Trek!" It's in that vein. They're movies they went to see, but they wouldn't watch them every week.
TNG is their sweet spot. Not mine. But theirs. So they'll either love it because it's more Picard, or they'll hate it because they'll be like, "What have they done to Picard?!" If they're onboard with the Picard Series, I'll recommend to them to give Discovery a look. Or I'll invite them over for a get-together to get them hooked with they're most receptive to it. I already hooked a couple into the series using that strategy and by talking it up in general.
But all by itself, I don't think a Pike Series would get more fans than Discovery, just some different fans, with a ton of overlap. It might drive up CBSAA Subscription Numbers a little, but not by much.