This initially simple thread has branched into at least three separate and unrelated issues:
Downloads and installs of 5005565 were
extremely slow for some users. Reasons for this and possible solutions/remedies have been discussed.
The Enablement Package was a way for the non-insiders to bump up to 21H2; 5005565 did not bump users to that level, it just moved the index number to 1237. Insiders were offered 21H2 without having to use the Enablement Package. A lot of confused discussion of what the Enablement Package and the major update (5005565) actually
did, and
for whom ensued.
Installing 5005565 broke some printer connections, especially (if not exclusively) those between wirelessly connected machines and their printers
if their connections were routed through a wired-connection machine. If the printer is wirelessly connected to all machines, 5005565 has no impact on that connection. In cases where the printer is connected to the router, and all machines connect to the printer through the router (wirelessly) there was no impact. The bottom line on this seems to be that if 5005565 is uninstalled
on the wired gateway computer (the one through which other machines gain access to the printer in this setup) but left installed in the others, there is no impact.
I'm not absolutely sure that's all absolutely correct, but I hope it is, and I hope this summary will help to resolve some of the multi-topic muddle this thread has become.