Will I still be able to update to the latest versions of EE?
Does anything change?...
Will they require me to upgrade to the commercial version of EE to be able to keep using it?
Any existing non-commercial licenses have been automatically upgraded.
As stated in their blog post ExpressionEngine License Simplification:
Previous license types have been upgraded for free. Whether you purchased a Freelancer license at $99.95 or a Non-Commercial license at $149.95, if you look at your existing purchases, you’ll see no differentiation. Your purchase has been grandfathered, and you now have the same download and same license as someone who paid $299.95 for the old Commercial license