Lectures have effectively been 'online' for years in most places. Prior to the pandemic, all our main-hall keynote lectures were recorded and uploaded onto a Blackboard system so that students could watch (and re-watch) them online in their own time.
It also meant that lots of students simply didn't turn up to the in-person, timetabled lecture - why would they when they could watch it at a time that suited them? It's also hugely helpful to those who struggle with the kind of fast, focused note-taking that is required in a lecture - they can watch, pause, rewind and rewatch anytime.
Seminars, tutorials, lab work, practical skills teaching, pastoral meetings - all of that will stay in-person. That's where the real interaction happens.
Any university worth its salt wouldn't need a pandemic to understand the benefits of blended learning.