If the original creator patented ANS and then just basically waived the patent for everyone, would that not help the situation with other implementations that are "close enough" to the original?
Generally no, simply publishing is enough prior art to avoid someone else getting a patent. It can be helpful in indirect ways, like being more likely to be seen by a patent examiner. Alternately, you can license it under a defensive patent license which is very useful in some situations (see e.g. Opus, AV1).
The only way of this maybe working I can think of is to patent ANS and license it for free to anyone with one exception - forbidden use by anyone who patents or licenses further patents on ANS. This would only leave out patent trolls, but at the same time incentivize everyone else to never touch patent troll patent and always fight them to the death.