I would say the word residents is important here. Building managers need to know who is actually living in the building for lots of reasons. Emergency situations being the most pertinent. It really is in your interests that the BM has a current contact list of both email & mobile numbers.
Increasingly I find people prefer their information via text message rather than email. Our building management portal allows for bulk messages to be sent out – this is used for important messages only. As a committee, our expectation is that the BM would keep the contacts list relevant. It helps us better manage the building and communicate with the residents in a timely manner.
It is unlikely that the strata manager will have an up to date list of tenants.