NEXT TIME GET ADBLOCK, COW!
I watch quite a few people that live off of streaming ads, so no.
That only happens if you're a partner iirc. Standard uses have to put up adverts so Twitch can pay for their services (servers, etc).
Same with every streaming service these days: Youtube, Own3d, etc
I've never seen an ad on a non-parter video on youtube, I thought it worked the same on twitch.