I don't think spectrum repack impacts any of the San Diego TV stations other than UCSD-TV, which elected to go dark with their LPTV (they are still available on cable).
I now see that KGTV broadcasting on channel 20 is KZSD-LP, a low power translator station for KGTV located on Mt. San Miguel (https://en.wikipedia.org/wiki/KZSD-LP).Noticed that KPXN has completed their transition from channel 38 to channel 24. I also see that KNSD is broadcasting a test signal on channel 17 in preparation of their transition there from channel 40.
Oddly, I also see KGTV broadcasting their four subchannels both on channel 10 and channel 20 (low power). I don't know what the channel 20 is, but they should use different PSIP channel numbers. My TV does not like two 10.1, 10.2, 10.3, and 10.4 channels.
That site you mention has an expired domain, at least when I clicked on the link.I came across this (http://sbe36.org/2019/02/local-dtv-stations-on-the-move/) about the repack. Looks like March 14th is moving day in San Diego. Why is it that the TV stations do not publish this information (KNSD excepted)?