You would be the absolute first we have heard of. Fantastic news, which tells us MCU1 refurbished units are no longer being used AND MCU2 upgrades for AP1 cars should soon be availabile.
We don't know anything from such a small sample size other than this person got a MCU1 to MCU2 upgrade free under warranty. Speculating anything beyond that lacks enough data to be even relatively accurate. We need more data points and a larger sample size to conclude anything further.
It very well mean that that particular service center rep ordered the wrong replacement. It could mean they had a temporary supply issue with parts used to refurb MCU1 units and they issued a temporary MCU2 replacement contingency plan. See my previous post about how this may be good news but only if the trend continues.
It's bound to happen eventually but I'd be surprised if we were 100% in the MCU2 replacement phase already. It's also possible that the NHTSA investigation isn't going well for Tesla and they're making a more accelerated "voluntary" transition to the newer MCU as a result ahead of possibly being forced to do so. It's fun to speculate at this stage since it could benefit all of those with MCU1 but let's not get reckless in our speculations making it seem like it's fact.
But, again, I'd wait to proclaim the days of MCU1 replacements gone forever until we have a larger sample size.