Ooooh it's soo salty, delicious.
It is! They're basically saying they don't want to be part of the community but they want the voucher. That's fine but then you gotta wait until the staff sort out the lower requirement section.
Also saying "link customer and forum accounts together." is easy when you don't have to actually implement it. There are risks involved (GDPR, security flaws possibly introduced etc.) so any solution linking is far from easy when you have personal data there.
I did have a think of how it would be done and one way would be for a SQL table to be made on the forum database which would add users to the table who qualify for entry (so select the user id, username where the date joined is greater than the minimum time length and the number of posts is greater than the post requirement. Could also make it that they have posted x amount over a certain recent period like 1 year etc to make it for active members).
Then basically that would run periodically updating that table of qualified members, and allow a lookup for the shop software to verify an account can use a voucher.
That would potentially reduce the vouchers to be being used only by members of the forum, as the vouchers right now could be leaked and thankfully it doesn't look like they have been.
It still isn't easy to implement as this is all assuming the shop discount system can validate a voucher based on whether your shop account has a forum account linked. Which is probably why it hasn't been done.
The easiest way would be to use the forum software to allow access and I guess that's what they're doing. However that way doesn't reduce the code getting posted out with the lower requirements, and I have a feeling that's what will happen with the lower requirement section when it's implemented.