Yes, but not without [grid] tags. Automatically converting images into a grid without tags would violate the CommonMark spec, we very much prefer to avoid that. (In my first internal draft of this feature, I did start with an automatic grid.)
Instead, what I have been thinking as the next step here is that we could automatically add the [grid] wrappers to uploads of multiple images, probably 3+ uploads. This would be especially useful for mobile uploads, adding tags manually on mobile is clunky and chances are that if you’re uploading 3+ images at once from your phone, they are photos and reasonable candidates for a grid layout.
We don’t have any plans yet for when we are going to add this, but it’s certainly something we’d like to do.