Per se, the only practical impact this has is if a player gets a WADA suspension, his time in the KHL will not count towards it (see recent case of French international Jules Boscq who was told his suspension would be held off until he returns in an IIHF-sanctionned context if he stayed in the ECHL last season).
I'm not denying any of this, I'm just pointing out the only real difference there is between the KHL (and, I assume, the MHL and ZhHL) being an IIHF-sanctionned league and becoming independent. Otherwise, it's pretty much business as usual.
It all depends on what the higher ups will want whenever the current situation evolves. Right now, it feels more like ego stroking as the impact is minimal.
I can not agree with your definition of "only practical impact"
This law allows the KHL to organise their scheduling as they wish. They are not limited anymore by IIHF events like World Championship. Next season will finish their playoffs in May instead of April 30. Btw. scheduling is a big issue for other top European leagues as well.
The KHL is outside IIHF transfer rules (aka IIHF transfer card is not needed anymore) as NHL has always been. The IIHF has no jurisdiction over KHL clubs & players.
The KHL does not need approval from national hockey federation (of country) in case of the expansion.
The IIHF Council and European member associations have done wrong decisions in last couple of years. This will have just one long-term effect -- they will become irrelevant, so weakening their role within world hockey. All they have done will weaken them. Especially without money due to incoming hardships.