If I interpret that post correctly (and I'm not sure I do, because it sure reads like it was written by someone who doesn't really know what they're doing and has an axe to grind), they submitted a request for both IPv4 space and IPv6 space at the same time, and ARIN wanted to go through the approval process for IPv4 first. This is understandable and not surprising.

At the end of the post it even says "Nothing stopping us from paying 1250 a year for our own IPv6 space though.".

This is an angry, confused individual upset about costs who decided to go rant semi-coherently on a forum full of people I wouldn't trust to administer a network anyway. It is not a reliable source of information.

Any notion that you require an IPv4 allocation to get an IPv6 allocation is wrong, was wrong in April 2012 when that post was written, and as far as I know, has always been wrong. You have never required an IPv4 assignment to get an IPv6 assignment, such a policy would be absurd and utterly counter-productive.

This is the ARIN policy document in place in April 2012: https://www.arin.net/policy/archive/nrpm_20120210.pdf

I can find no requirement that new IPv6 allocations require an IPv4 allocation. See sections 6.5.2.2 and 6.5.8.1, which correspond to the pages I linked to earlier.