Regardless, a merged pull request on the Chromium Gerrit reveals that Chrome for Android will most likely start disabling scripts on slow networks. The corresponding document on Chrome Platform Status fully explains the feature:
If a Data Saver user is on a 2G-speed or slower network according to the NetInfo API, Chrome disables scripts and sends an intervention header on every resource request. Users are shown a UI at the bottom of the screen indicating the page has been modified to save data. Users can enable scripts on the page by tapping “Show original” in the UI.
I was unable to test this feature on my phone, even with an emulated 2G mode in Chrome Dev Tools. The Platform Status page doesn't list a browser version, so it's unclear what Chrome update will have this enabled by default. The relevant flag (#enable-noscript-previews) has been in the browser for several months now.
- XDA Developers