Not true... sort of. When you install AVAST, as all antivirus, browsers, & most software, you are offered to opt in or out of data collection to help improve the product. If you opt in, AVAST does not collect your name, address, email, or ISP information. They, like most software companies may sell those anonymous data statistics to others.
If you're not sure what you opt in or out of during the installation of AVAST, or change your mind, the opt in/out selection can be easily found in your settings, along with any other configration setting you may wish to change. Many other software companies hide the option well so it's hard to find, or don't offer the option to opt out at all.
Even windows 10 has some privacy options, but the worst privacy intrusions are well hidden & confusing, where they deliberately make it unclear what you're opting in or out of, or require almost some "engineering" to opt out of or stop. No matter what you do to W10, no matter how you set it, it will still record your every keystroke, & send it to Microsoft, along with your Microsoft ID.
It doesn't matter with W10 anyway, because they change your settings to whatever they want to in a future update without your knowledge. So with W10, you literally have to check your settings 24/7 because MS will change them without any notification.
Uninformed techie wannabes, & knowledgeable tech news sites are hyping this AVAST data option as some sort of scandal, while this sort of opt in/out of data collection has been used by most software companies for over 25 years, & has always been quite common.
If you don't want data collection in AVAST, Firefox, Pale Moon, or Waterfox, just opt out of it. It's a choice, not a forced, hidden, or secret thing. Many software, antiviris, & browser companies aren't so up-front & transparent about it, or don't make it easy to opt out.