Yes you are absolutely correct.
As a rule of thumb here we release "Update N" as just a Managment Pack update, when we update a backend services we would change the version number. So it's expected that version number for UI will be the same, however in SCOM console some of updated Management Packs should have bigger version number. Here is how it looks in my lab:
Keep in mind that we also have OMS Integration in the Update 4, all the releated info can be found here
Also keep in mind that for SCOM 2016 Management Pack Installation behavior changed
- you have to import only Management Packs with increased versions, check them on the screenshot above.
Let me know if you still ahve any issues with installing Update4