Like IPv6 specified in the early 90s fully replaces Ipv4 with time.

Like reiserfs has become the standard Linux file system. Like btrfs is becoming the standard Linux file system (Redhat has announce to discontinue support)

Predictions are difficult, especially when they cover future developments...

Not really for the type of VPN AirVPN provides. Wireguard (still) has many issues in that area, some of them foundational.

Unsure what the downvotes are for.

Wireguard is not designed to provide any obfuscation. It has very clear fingerprints. This is by design. Jason is very clear that Wireguard does not consider obfuscating its packets to be in scope for the project.

AirVPN (I believe) attempts to provide a service that also features an obfuscated / hidden VPN.

This does not mean that Wireguard cannot become the underlay used by VPN providers like AirVPN. Just that they'll need an obfuscation overlay as well.

By "obfuscation" do you mean a way to disguise packets sent as some other protocol? What methods does OpenVPN provide for this?

I use wireguard with Mullvad since it launched without issues. They even have it in the official client. I talked to them about the article that one VPN provider wrote about it not being scalable and not privacy preserving and their response was that it was mostly FUD. I believe one of their technicians wrote a blog about it, but now I can't find it.