As I see it, the word 'Segwit' can have 2 different meanings now:
1) Bunch of improvements packaged together in the latest release of bitcoin-core;
2) Segregating signatures from the rest of transaction data (segwit itself).

While clearly many of the improvements result from signatures segregation, do all of them depend on it? Or are there some, that are implemented independently, that don't need signatures segregation? If all improvements depend on signatures segregation, then there's actually little sense in distinguishing the two meanings one from another.

Edit: In other words, can some of the improvements be implemented as a separate softfork, or maybe even without softforking at all?