Remember what T'Pau warned Kirk? That he might be disturbed at what he was about to see, but it was Vulcan custom? Well, at that point, T'Pring hadn't yet made the challenge. So what was T'Pau referring to?
The author of the essay reminds us of what T'Pring was wearing... a rather unusually-cut dress. Spock was in a hurry to get on with things. He was embarrassed about the whole situation. For these and other reasons which I can't recall (it's been many years since I read this essay), the author speculates that the marriage would have been consummated right there, on the spot, in public, in front of everybody.
Now that doesn't seem reasonable, given what we know of the Vulcan intense preference for privacy. But to what else could T'Pau have been referring? She didn't know that T'Pring was going to challenge. A normal exchange of vows wouldn't have been something that would have been "disturbing" to off-worlders. So this is one of the mysteries of a normal Vulcan wedding that we are never told.
Purely speculative, but certainly not out of the question.
Given Spock's state of mind (which seemed to be pretty much the Vulcan norm), I would even call it plausible. Would help explain why Vulcans in general are so reticent about what, logically, is 'merely an involuntary biological imperative'. Which is, I am absolutely certain, how Vulcans would calmly refer to this state if seen in another race/culture.
I also suggest that there could be some degree of variation in the whole deal. Vulcans seem (like a lot of Trek aliens) to have a monoculture - there are no apparent variations in their culture and traditions, as far as we know. Other than the few small dissident groups, that is.
But, important as traditions are in Vulcan society, it may be that some Vulcans "keep to the old ways" more thoroughly than others. The ceremony in 'Amok Time' may be the fullbore traditional version of a Vulcan marriage (hate to think it is actually the "reformed" or "modern" version
Yeah, lots of "may bes" and "could bes" in all that. Just thinking out loud, really.