Not whom you asked, but I also don't believe this ad is effective.
1. Show, don't tell. The "What's a computer" ad, hated as much as it is, shows a kid actually doing fantastic...kid stuff. Video chatting with friends, taking pictures, drawing, writing a report for school, geeking out on bugs. She's obviously smart, independent, and talented. The Microsoft kid sings, dances, and swipes and tells everyone how smart she is. Code rolls by. Nothing is actually done.
2. Insulting. No, not insulting toward Apple. It's insulting to the grandparents (and other older adults) being targeted, who probably have and use an iPad or iPad Mini. This ad does not take into account how many people have been exposed to iOS. Nana will probably call BS on an iPad only being appropriate for a six year old since she uses it in many of the same ways as the iPad kid.
3. Poor Targeting. I still have and occasionally use the sibling of the Surface Go, the Surface (non-Pro) 3. I've always thought that this size and form factor was the perfect computer to pit against the MacBook. Work on the battery life, add some additional targeted features to OneNote (beef up it's PDF capabilities and export features), and create education (high school and university) and enterprise bundles. Yes, there are some pre-teens who would benefit from a Surface Go, but that is niche. Meanwhile, the vast majority of high school and college students, and traveling business persons would have no problems with even the base model Surface Go.
I understand what Microsoft wants to do. They want to take advantage of the 'real' vs 'toy' argument going on between PCs and iPads. And that's a good idea. But, instead of featuring a singing 10 year old, show something that at least appears to be more real. They could get away with an ad suggesting that iPads are great in elementary school, even a Chromebook is fine for middle school, but in high school? I need a Surface Go. Hell, feature triplets in high school. One, a geek, coding. Another, doing art and design. The third? They are the business oriented one, using Office to sell the app the other two just designed.