Honestly, Stranger Things Season 1 is one of the best seasons of television ever made. 2 and 3 were good, but ultimately were missing some je ne sais quois from the original. Like they were fine shows, but they felt more like high-quality fanfiction based off of the original, rather than direct continuations. Having this long of a break between 3 and 4 makes me a lot more hopeful that the writers really took their time to make this the best it can be.
Really, when I was speculating about what season 4 would be, I was actually hoping for a bigger time jump, and for it to be more like a cross-country road trip in a beat-up old van to get the gang back together from all the different colleges they moved away to.
This doesn't look bad by any means, but some of the shots concern me a little: the biggest strength of season 1 that the other two lacked was that the monsters were very unknown and very rarely seen up until the very last minute. In season 2 and 3, the monsters became such 'known entities' that they weren't nearly as exciting. The fights against them were usually really damn cool (the fireworks scene in the mall near the end of season 3 was an absolute blast), but the lack of mystery made it a little less engaging than the single demogorgon from the first season.
This trailer barely showed the monsters at all, which is perfect, but the shots they did have looked a little more like they were in the middle of big action spectacle set pieces, which makes me worried they'll do the same thing as before and make the monsters more 'cool' than 'scary'.
All that said, I cannot imagine this being a bad season of TV by any means, and that red temple at the beginning looked super sick and I'm really excited to explore the more intelligent entities in the upside down.