Not really, it was experimental and only released recently (end of last year?). You can't really build experimental features with potentially breaking changes or even a complete removal into a CI pipeline without a lot of risk.
The main issue with Cypress handling this is, from what I understand, one browser per domain which can cause huge memory usage (which Cypress already has an issue with). Once you try parallelising multi-domain tests you run out of memory on developer laptops pretty quickly :(
But yes ultimately you are right, multi-domain is available, it's just those edge cases that get you once you go beyond simpler cases.
3+ testing tools for websites - Selenium, Cypress, and Playwright.
Selenium is a little old and verbose - the biggest issue, imo, is having to handle waiting for elements. Also managing webdrivers suck. Cypress is great for E2E tests but falls apart on edge cases, for example it can't handle multiple domains. Just requiring npm and not needing webdrivers is really nice for CI. Playwright is sort of a combination of both - fixes a lot of issues in Selenium but has the ease of use of Cypress. It is much less documented than Selenium though.
If I was starting a new project I'd use Playwright.