Why does YouTubers say "This portion is sponsored by..."?

Lately I have noticed more and more YouTubers have stopped saying that the video is sponsored by and instead says that this portion is sponsored by

At first, I thought it meant the video would / could have multiple sponsor and the sponsor only paid for portions of the video. That's not the case, why many YouTubers have changed how they say it

According to Linus Sebastian from YouTube channel Linus Tech Tips. It's sponsors agencies buying advertisements, that want to secure that the sponsor is not associated with what possible controversal content of the rest of the video might contain and to avoid negative impact on their brands

There's no legal requirement to phrase it like this and it's only some sponsors that want it phrased like that. In reality they're sponsoring the entire video, even if the phrasing says portion of the video