There are more name Easter Eggs than just that one. Timeless has a character named Lucy Preston. Bill and Ted’s Excellent Adventure has a character named Bill Preston. Timeless has a character named Wyatt Logan; Bill and Ted’s Excellent Adventure has a character named Ted Logan.
This has been confirmed in an interview with Abigail Spencer, who plays Lucy Preston:
PS: I couldn’t help but notice that the three main characters have
similar names to the characters in the ‘80s movie Bill & Ted’s
Excellent Adventure. Is that purposeful?
AS: Yes! Good for you. You’re one of the only people that have caught
that. With Eric and Shawn, everything is purposeful. There are Easter
eggs all over the place. They are so good about weaving in other shows
or other characters or other stories, and they’re doing that on
purpose. We want to be part of the time-traveling family. We want to
be in line with what was created before. So yes, there are some great