The objectives have changed.

Previously, large tech companies were interested in hoarding employees to slow competition.

Now, that is no longer a necessary strategy as the environment has changed and smaller startups have many other headwinds (difficult to raise $, etc).

So as the previous strategy is unwound there will be more pressure on employees and attrition is definitely part of the plan. A side benefit for the companies is less upward pressure of salaries and operational savings.