Please send such requests to the list admins at vger.kernel.org directly.
I do not think people that are active on this list do not have much
influence on the filtering policy, and also I suspect not many list admins
read this list to trawl for request like this.
Having said that, I personally would not want to see non-text messages
myself, even though I often find myself not having any access to the list
but via gmail and I find it quite limiting. But I tend to consider that
not allowing pure text messages is a gmail bug/misfeature and needs to be
fixed not by allowing html cruft on the list, but by enabling poor gmail
users to send pure text when they want to.
Yes, I sit in Mountain View, but I suspect that pure text messages are not
anywhere near the top of the task list of the people who run gmail, and I
know I do not have much influence on that matter, either.