As far as the media reboots go, those are all a matter of personal preference. For me, I grew up on TNG, and I love the continuations in the Trek universe. Discovery keeps getting better and better, and I'm looking forward to the new season of Piccard. I also enjoy the movies, and I think it was very smart of them to introduce a parallel timeline so that they weren't limited by cannon to have the artistic freedom they needed. I've also thoroughly enjoyed all of the new Doctor Who episodes, with the exception of the last couple of seasons where I feel they've changed the feel of the show, but I digress. I never watched the classic episodes, so that isn't even a play on nostalgia to me. On the other hand, a lot of reboots, especially in the movie realm, are horrible. Matrix Resurrection for example was very blatantly a pull on nostalgia, to the point of breaking the 4th wall, and it wasn't great. And how many reboots of Spiderman do we need? Do we really need to keep making more movies in the Fast and the Furious franchise?
As for products, some of them make sense. Flip phones, for example, are making a comeback. We only went away from flip phones because the form factor wasn't conducive to smartphone technology. Now that we have foldable displays, I feel it is a great way to shrink phones back down in size so they fit better in pockets and are more convenient to carry without sacrificing the large touch-screen display that is needed for today's media-centric mobile use. They're still new to the market so it may be a little bit before the technology improves and becomes mainstream, but it is likely the direction most "phablets" will go.
I don't really know what you mean by tower PCs. Full-size towers never went away for gamers and people that need the highest-performance machines. If anything they've grown as people have added larger graphics cards, more hard drives, water cooling systems, etc. On the other hand, I wouldn't say they're making a comeback anywhere else. Most consumer PCs these days are using mini or micro ATX boards, so even if they are a "tower" shape, they're half the size or less than the standard from 15-20 years ago. I haven't purchased a full size tower for my company in probably 10+ years at this point, we've gone almost exclusively to laptops, all-in-one workstations, and single-board PCs that are small enough to attach to the back of a monitor on the VESA mounts. A lot of the enterprise push is going back to thin clients with the PC hardware itself virtualized in the cloud.
While I can agree with you that there is a lot of push for nostalgia in advertising and in many products right now, I just don't feel your examples were very fitting.