I see a lot of Dark Souls comparisons, but, outside of the resting/respawn mechanic, I don't find it very similar to DS. I think the closest comparison is Metroid + Tomb Raider.
Metroid's a 2D or 3D shooter, so I don't get that at all. Tomb Raider covers the "Metroid style map design" since it does the same thing. Dark Souls comparisons are for parry and dodge heavy combat where you need to avoid damage, the respawn mechanic, the health flasks, the optional tougher enemies guarding best "loot" (in this case health upgrades and such), and it also had "Metroid style" level design. That's a lot of inspiration to be written off.
By "Metroid", I mean metroidvania. Judging by your "
Metroid's a 2D or 3D shooter" comment though, I'm guessing you've never actually played a Metroid game.
I'm not writing the DS inspirations off, but Fallen Order is still more metroidvania than Dark Souls. Tomb Raider doesn't cover the map design unless the last couple of TR games, which are the only ones I haven't played, are dramatically different than all the other TR games. Even if that's the case, it only shows the influence metroidvanias have had on TR as well. One of the primary aspects of metroidvanias is that you can return to anywhere you had previously been in the game. You rarely, if ever, return to previous locations in TR. In fact, prior to the 2013 reboot, TR games were completely linear in that you advanced by finishing one location and then going to the next without ever returning. Where the TR influence comes in is the platforming and puzzles.
Combat has obvious similarities, but there are too many games nowadays that have this kind of combat to call them souls-clones because of it. Also, the difficulty isn't even close to souls level, and that's a primary aspect of being a souls-like. You also mentioned optional tougher bosses guarding the best loot, but I'm about 60% finished and have yet to see that in Fallen Order. The "loot", if you even want to call it that, is simply hidden in out-of-the-way nooks and crannies.
I get why people are saying souls-like though, and I don't have a problem with it. DS itself is an evolution of metroidvanias with the level-design and shortcuts. The difference is that areas are gated by enemies rather than needing a new power or upgrade to advance, and that's exactly why Fallen Order is more like a classic metroidvania.