This is true. If you have DMARC and your RUA set up (with a working email (or one that doesn’t bounce at least)) along with SPF and DKIM, Google and MS will accept your mail. The only time it won’t at that point is if your IP is in the same /24 as a known spammer but so long as the spam stops, you’ll fall off the list. Some of the common spamlists allow you to request your IP be removed by request and I can only recall one list that almost nobody uses that makes you pay for the removal though there may be more I don’t recall.
You need SPF, DKIM, DMARC with a RUA set up to an email that doesn’t bounce. That’s pretty much it. I’ve been running email servers a long time and actually set up email from a new domain/IP a couple of years ago as well.