I defer to the developers. I'd like to say that explosive traps aren't a good idea: machines tend to malfunction, and I wouldn't want to live in a base with explosive traps that could go off by accident. If these can be applied safely, and according to well-tested, existing models, then I'd say it's consistent with the game.
Automated defences were great in XCOM 3, but aren't consistent with the UFO:AI universe, as far as I know. Some automated defences are possible, but nothing that would make having good agents in a base necessary to defend the base.
Defensible points are very believable: some kind of bunker or such emplacement to enable the player to assert a defensive advantage. We know they're going to raid our bases sooner or later; we should be able to prepare in some way. Certainly, we ought to be able to achieve some level of chokepoint defence by means of careful base design. I believe this is possible, and may be augmented by a defensive position to be occupied by agents. I'd like to be able to create two such points: 1 primary, and 1 for fall-back. Nothing super-mated, nothing that means you can have otherwise un-protected bases. I've always been a stickler for a backup defensive position.
I'm sure the developers are doing better than I can suggest. I know I'm wary of having too many entrances, and I'm not sure how many doors a super-secret installation would have, but I don't know what the developers have in mind, so I'll wait and see. I think the purpose is to strike a balance between terror, and the potential for good planning, experienced agents, the best equipment available, and excellent tactical discipline to counter-act that terror.
Terror - that's what the XCOM and UFO:AI genre is about. The terror that the aliens will conduct terror attacks at night. They will kill civilians every chance they get. They'll kill your agents every chance they get. And they'll raid your base and kill your agents in their beds if they get half a chance. The point is, that PHALANX fights that terror.