I was working for a company that was interested in releasing some of these recordings on DVD and Blu-ray about 10 or 12 years ago. We did release a good number of productions that were taped later in the runs for commercial release. I had a number of conversations with involved parties, but nothing ever happened.
Some of the reasons were: While a lot of the shows were taped in their entirety, the purpose of the recordings was to cull clips for promotional purposes (like the tourist broadcast channels that play in NYC hotels, etc.). They were generally shot with fewer cameras than would've been used for a pro shoot. Since the shows were shot very early on in previews or rehearsals, etc., it was thought that some of the performances were not ready to be immortalized. Another excuse/reason I heard a few times was that the producers were considering a future movie adaptation that they thought would be negatively impacted by having a recording of the Broadway show in the marketplace (not one of the shows I was in contact with ever ended up becoming a regular "movie"... ).
There were other issues, too. It's nice to see that LCT is able to make some of these productions available to us. I wouldn't expect to see many other offers like this as many of the performers, etc. did not originally sign off on commercial releases of these recordings. As you may imagine, music rights, etc. also come into play here. LCT is probably able to offer these productions as they are offering them free of charge. They will gather email addresses in order to market future productions, etc. once theatre is up and running again.