Fixed is much too strong a word. Mitigated is more descriptive. From your link:
> This fix is widely seen as a stopgap measure, as it only makes the attack up to 65,536 times harder. An attacker willing to send billions of packets can still corrupt names.
> This fix is widely seen as a stopgap measure, as it only makes the attack up to 65,536 times harder. An attacker willing to send billions of packets can still corrupt names.