Just listened to an interview with the Facebook founder. His rapid alternation between high and low tones reminds me of, just, slow motion yodeling. Is this type of intonation becoming a trend?
If you provided some kind of link to an audio or video file, then perhaps we'd have some idea what you're talking about.

If you even provided the name of the person you're talking about, there might be someone bored enough or helpful enough to hunt for a link to an audio or video for the rest of us to listen to.
In any case, OP, have you heard other people doing what you describe (whatever it is)? If not, it probably isn't becoming a trend.
The description sounds like a boy whose voice is changing and he can't yet control the register. But without a link, I'm as clueless as the rest.
OP - are you talking about Mark Zuckerberg?
One link from when hewas on Oprah. He appears about 1m20s in. To be honest, I can't hear anything unusual in his voice/speech other than perhaps a tendency to speak with an upward inflection.
Actually, after a brief googlesearch it does appear that there are numerous pages referencing his speech and an upward inflection or intonation.
On that note - is an inflection the same as an intonation? I assumed for this purpose it is because it appears to have the same definition. But I would happily be corrected.

OP here. Yes, I am referring to Mark Zuckerberg. (My first message showing his name was rejected so I deleted his name.)
Wikipedia defines yodelling as " an extended note which repeatedly changes in pitch from the vocal register to the falsetto /head register" which is exactly the way Mark Zuckerberg sounds to my European ears. I don't think I I have heard any European speaking in this way. But I have heard a couple of other examples on Internet, both were Americans and about Zuckerberg's age. So I wondered whether this is a US trend.
