It's a statement in support of suppressing speech, and it's needlessly political. Mozilla leadership has mostly rested on their laurels (read: Google money) while Firefox consistently slid in market share. I've been a loyal FF user for 17 years, and this was the final straw. In the process of switching to Brave.
I don't see anything in that post about suppressing speech—can you help me see it? The main bullet points in the article don't seem to have anything to do with suppressing speech (unless that is how you are framing the bullet point which reads: "Turn on by default the tools to amplify factual voices over disinformation."
It starts with title "We need more than deplatforming" which means "deplatforming is good, but it's not enough".
noun: deplatforming; noun: de-platforming
the action or practice of preventing someone holding views regarded as unacceptable or offensive from contributing to a forum or debate, especially by blocking them on a particular website.
It continues with "Changing these dangerous dynamics requires more than just the temporary silencing or permanent removal of bad actors from social media platforms."
Blocking, silencing and removal does suppress speech.
Freedom of speech should not guarantee 'right to global reach'. People should be allowed to say what they think to an amount of people who they can have personal relationships with, their neighbors, relatively close colleagues and similar. Deplatforming should not take this away, it should just take the biggest megaphone away mankind invented to date.
Sure, in the same vein as building a dam is water suppression. It doesn't take away any right, it's about the limits of a right.
You also suppress freedom of speech indirectly when you put someone in prison, so any crime punished by imprisonment seems to be considered reason enough to justify that as well.
Saying that freedom of speech can't ever be limited is a very ideological point of view, so far away from reality that I wouldn't consider it worth debating at all.
Now there is a valid argument to be made, how decisions to deplatform a person should be made and/or how such decisions can be appealed.
Deplatforming isn't suppression it's realising that you entities do not have to be neutral in their support and broadcast of various things. It's the question of a radical over a liberal mindset.
The Mozilla of 2004 is not the Mozilla of today. With unnecessary proselytizing/virtual signalling, implementing features antithetical to their values (Pocket integration, switching to WebExtensions), pursuing wasteful and fruitless endeavors (FirefoxOS), the company has completely strayed from its main focus: building a solid, open, and free browser. I'm still with them, but I'd be lying if I don't strongly consider moving to Brave every time they come out with actual innovative and exciting features like this.