Pretty sure he's right as far as the likelyhood of repair goes: it will never be repaired, the whole module will be repaired. Which means some pennies are to be saved by elimenating a few bolts.
You may not like it, I may not like it but that's how it goes. Last year, I was supposed to fork over 1600€ for a new adblue assembly. Only the pump was shot. No possibility of acquiring a pump. Anywhere.
Yeah, but what happens to the unserviceable unit after the replacement goes in? I'm not saying that it doesn't go straight to scrap or recycling, but with things amenable to component level repair it's not beyond belief that they get fixed and become "service replacement" parts the same way as happens with engines. In the particular case of inverters, there's a high likelihood that the problem with a broken unit is just a blown IGBT module*, and that is surely an easy and economic component level repair, one that could be done as a "stock repair" even if one wasn't going to go in for more detailed and fiddly component level repairs.
Keysight only do board level repair of customer kit that's sent in nowadays. However, TiN and others have found refurbished boards sold as replacement parts by Keysight for the 3458A. If the part's valuable enough, and the stock fixes identifiable it makes sense. I'm sure that they don't refurbish
all boards, only ones where the fault is an easily diagnosed stock fault and the value of the board is high enough to cover the cost of rework.
*The IGBT modules that I've seen in these kind of inverters are the ones that are beefy enough to have to be bolted in during original construction, not soldered, which makes it an even easier target for re-work.