Edit: This could very easily be from AdBlock Plus as well, but the tooltip was under the address bar (and it doesn't reappear when I visit reactos.org)
Edit2: I got this when navigating to https://goggle.com also (that's goGGle, not google). Turned off Lastpass and Adblock Plus to confirm it wasn't from them.
More than 3 times longer. ReactOS was started in the 90s (in fact I might have even used ReactOS before I first used Linux. There certainly isn't much between it). Whereas React.js was started in 2013 (ref: Wikipedia).
But for legitimate communities building honest software (or any honest product, really), it can be harmful to have potential users/contributors being scared off by a message like this. At the very least, it can make visitors question the legitimacy of the product. Since ReactOS has been around for decades at this point, it seems as if they're suffering a penalty for not being as popular as ReactJS, which is kind of bullshit, if there's no way for ReactOS (and other legitimate companies which may be affected) to let Google know "hey, we're doing our own thing, would you please mind not scaring potential users away". Whether or not I use Chrome, at least 60% of Internet users do. And I've never seen a warning when visiting reactjs.org asking if I didn't actually mean reactos.org, so the axe doesn't swing both ways here.
Well, you just reiterated that ReactJS is newer and newer is always better. /s
The best way to avoid having Google interfere with your browsing is to use a non-Google browser.