Gary Illyes, from the Google Search Relations team, said on LinkedIn that Google Search handles the marquee HTML tag "appropriately." What does it mean by appropriately? That is Gary for you.
I assume it means Google can read the text within the marquee HTML tag.
The marquee HTML element is used to insert a scrolling area of text. You can control what happens when the text reaches the edges of its content area using its attributes.
Google even has this long standing marquee tag new easter egg that looks like this:
Here are some funny comments in the LinkedIn thread:
Again, Gary wrote, "Please note that, after digging through some ancient code, I can confidently confirm Google handles marquee tags appropriately. You're welcome, internet."
Forum discussion at LinkedIn.