The London production of
Harry Potter and the Cursed Child was recorded for archival purposes during its two Wednesday performances, fans at the Palace Theatre noted on social media. Some of those updates can be found here.
As the second photo shows, the original cast of the
Cursed Child, including Jamie Parker (Harry), Paul Thornley (Ron), and Noma Dumezweni (Hermione) took part in Wednesday's performance, which will one of their last before their final run on May 21st. After that, the new cast will join the West End shows.
Do note that this filming is not being done so for public consumption, and there is little to no expectation that it will be released on DVD/Blu-ray/digital or any other platform. Many stage productions, on the West End, Broadway, and others, have been recorded for similar archival reasons.