tl;dr, podcasts are expensive to produce, about $1000/hour with video, hosts (local and remote), and post-production. TWiT is going through hard times and some shows and hosts have to go. Sadly, FLOSS was on the chopping block.
Advertisers just aren’t interested in podcasts anymore. If you still want to support the network after this, give Leo $7/month and join Club TWiT. I don’t give a rat’s ass about Discord, but I do want to prevent stuff like this.
That firmware part isn’t new. Back in the day when we were dual-booting Linux on PowerPC Macs, macOS was still needed for firmware updates.