Shitty advert IMO but no reason for it to be banned.
My mother taught me about periods. Yet when it happened, I still hid it. Got piss took out of me as people could 'tell' I had pads on at times, so tried using tampax, just kind of..kept trying until I got it right. Had a few very uncomfortable days where it was kind of half hanging out as I figured it would hurt too much putting it in 'properly' (obviously at the time I didnt know it was properly, just seemed..too far in!)
I have tried very hard to start talking about stuff like this early with my daughter just so she knows, and knows she can come to me with anything. She is only 7 and knows a fair bit about periods, possibly more than some teenagers know tbh. Son knows too though it won't affect him, hes walked in a few times during the convos and it seems daft to just stop and hide the convo as if its something to be ashamed of. So my 6 year old son potentially knows more than a teen girl too.
Even with this though, theres the chance when it happens she might hide it still. I knew I could go to m,y mother abou8t anything, yet for some odd reason I still hid it..cannot understand it but I did feel ashamed in a way, ans very dirty, even though I knew it wasn't.