I'm sure people in the UK are doing launches, but it's illegal for them to transmit when flying in UK airspace.
In reality, it's an almost unenforcable law to begin with. Most of the WSPR transmissions are on the order of 10mW (probably similar to the Bluetooth output of your cell phone). It's not unusual for these transmissions to be heard several thousand miles away, which is quite amazing!
If I remember right is the reason is that it’s illegal do use amateur radio bands on something that is flying, so that excludes APRS. However, using the ISM bands are fine so that’s what people in the UK tend to use, but it means no APRS and you have to have people tracking you in other ways (e.g. sending your telemetry over LoRa or RTTY)
In reality, it's an almost unenforcable law to begin with. Most of the WSPR transmissions are on the order of 10mW (probably similar to the Bluetooth output of your cell phone). It's not unusual for these transmissions to be heard several thousand miles away, which is quite amazing!