I would be more surprised if tech companies stick to remote work first. Remote work has been doable in tech for a long time. However, it comes with the same issues as off-shoring - in particular, how do you know that the person you hired is competent, committed, and honest?
Yes, there are ways to answer all three of these questions, but I'm not sure if there's a way that's simple, non-invasive, and scalable in organizations dealing with lowest-common-denominator challenges. Many startups and smaller IT companies were already doing remote work before COVID - but, let's face it, many of these companies also had a small enough footprint in terms of head count and job diversity that it was possible for them to manage 10-100 remote employees without running into major issues.
How do you do the same with 5K-10K employees? Yes, FAANG is taking a shot at it, but they also have the benefit of hiring their pick of top-level, motivated talent. Google and Facebook, at least, also have revenue streams that are resilient enough to survive massive mistakes purely through inertia.
This is an interesting natural experiment. I'm glad that it's forcing companies to reassess how they do business. However, I don't know if remote work first is going to persist after the pandemic.