Got word from Mike himself:
Doesn't the racking without repitching leave you with a beer that's pretty low on fermentig agents for the better part of its ageing process?
Pretty much, depending on the batch. The microbes that fall out of solution are dead or dormant. It is the microbes floating around in the beer that do almost all of the work. They won't be left behind.
...
I don't chill, don't see a reason to. I'm fine with some Sacch making it to secondary. A little autolysis won't hurt. Some brewers who wait to secondary to pitch bugs do crash, fine, or filter.
So: racking is done just to get the majority of the cake out of the way. Anything still in suspension at fermentation temp is expected to be hail and alive. The Sacch will start dying off eventually, and the Brett will eat the autolysis products. All the while, L&P will be producing acidity and whatever flavour components they're expected to deliver.
This, as homoeccentricus points out, under the assumption you're not using a barrel but are fermenting under glass.
Makes things a lot easier, really. Brew wort, ferment in primary with the whole kit&kaboodle, rack into secondary, add oak and fruit, and wait. I like that.
Only concern I have, and a good reason to pitch Sacch first and only pitch non-sacch once you've racked to (glass) secondary would be that this way your primary (and likely plastic) vessel doesn't become contaminated.