No. Google Maps works a different way.
Google Maps learns travel times by monitoring the pace of other riders.
The Google Maps app "constantly" sends data about your location back to the Google servers. It knows you're on a bike, not driving, because you requested a bike route, and because your travel time is not an outlier from other people doing the same.
And that's also true for driving; though of course Google gets more data for drivers, so driving data is fresher.
Yes, really. Google "spies on you" and observes your movement, nominally for this exact purpose (but they won't refuse a subpoena in most cases). And yes, you agreed to be a lodestar for others, at some point when you clicked "agree" on a term-of-service while interacting with a Google product. You can deny Maps access to your location, but then of course, it wouldn't work at all.
This tracking is fairly continuous, even when the screen is off, which means Google knows when you stop for a break, and excludes that time from the data.
This provides a very authentic transit time without having to do deep calculation on the effect of grades, tight curves, congestion and road condition on ideal travel times. For instance if a flat, straight rail-trail is heavily overgrown with brush to where you must slow to maneuver around a thicket of overhanging branches, it captures that reality.