Some updates:
Banners created in GWD (Google web designer) also are disapproved when GSAP library is inserted (via GWD menu "Click File > Include JS library > GreenSock." as mentioned in official documentation).
Of course all ads are tested in official google html5 ad validator, and they all pass it. Banners were tested also with Google Ads team and they agree, that ad is made correctly. But they try to understand why they are still disapproved in their system. We had phone conversations, tons of e-mails. Looks like an interactive ping-pong game. Looks like there's an error inside their own system, which is checking ads before pushing they live.
By the way, when my problem reached Google Ads team, they updated hosted library to the latest gsap. Unfortunately this link is still not white-listed in the system where our ads are going to.