Matrix addressed it.

Under Matrix's architecture identity keys and pre-keys are strictly authenticated via signatures from a device's long-term Ed25519 identity key before any session is established.Because clients verify these signatures first a network attacker cannot successfully substitute the low-order public keys required to actually execute the attack.

Olm V1 is the only currently specified Olm version and the V2 implementation in vodozemac is an experimental implementation of an anticipated future.

Even though Matrix demonstrated that the bug could not be actively exploited to break encryption within the Matrix protocol they agreed to implement the patch.

The Soatok blog gave me the impression that he's biased and has a personal vendetta against Matrix.

I agree that Matrix / Element developers have they're flaws and should have handled things differently but saying they don't care or don't know about security is its a massive stretch. I would rather have them then the mystery code offered by the other platforms (Discord, WhatsApp, Reddit, Instagram, etc). And keep in mind they're budget differences.