Yeah, you get one Series 4 cards within 40 box openings (so you can be lucky and get two back to back, or unlucky and open like 80 between two), so might as well make sure your Series 4 card is still Series 4. I’d be annoyed if I opened a box now to get She-Hulk who is about to be Series 3 and instead wait to get Shuri or someone else instead.
I got Titania, Maria Hill and Galactus so far, so I feel like another Series 4 is coming soon, so I’m holding until the drop.