To each their own opinion but may I ask what exactly sounds fun to you in those changes? I just had a quick glimpse again and the far majority are flat number nerfs, leaving only the change to Ignore Pain and RFDT as debatable.
About the Ignore Pain change you said you like the fact that "the better you are at generating rage the better you are at mitigating". That's already the case, as more rage = more Ignore Pain, nothing changes?
And what is it about the new RFDT model that you prefer? I gave the example of a typical hard and slow hitting boss which is what raid bosses are (not only this tier like you make it sound). It's the reason the T19 4piece with 5 rage generated on a crit block was considered not worth going for for raiding. Swings are not frequent enough for this to be noticeably strong. And for dungeons the internal cooldown limits its usefulness. There's basically no tanking situation in which the new model wouldn't result in a massive rage loss except if you're tanking M+3s in 940 gear maybe.
Most of all, it means our rage generation and therefore our survivabilty does not scale with the difficulty of the content we are tanking! This means you won't get more rage from tanking a really nasty hitting boss. Unless they balance it around that difficulty (in which case you'd be stupidly OP in any non Mythic raid content), this means we will have trouble adapting to higher difficulty modes.
Another example: As it will probably have an inner cooldown just like the T19 4piece, the rage generation won't really scale anymore with the amount of mobs you're tanking at once. If you want to do big pulls in M+ and you get the same rage from 10 mobs that you get already from 2 mobs hitting you, that's going to be a problem. Other tanks, for example DH, can adapt to that situation by being able to put Frailty on 10 mobs and aoe leeching the shit out of them, so they have scaling survivability.
If they don't massively overtune the numbers for the new Ignore Pain or the RFDT model, they're bad changes for us. Why would you find something fun that's bad unless it gets changed? Isn't it more prefarrable to keep something that doesn't need changing to be good?
Prot Warriors current philosophy is being incredibly strong at mitigating physical damage when you have Shield Block up and you don't show your back towards mobs at the cost of having a ridiculously low health pool and almost no passive damage reduction. So during Shield Block downtime or when you don't have rage yet on pull or when mobs might be hitting you from the side/back during kiting etc. you're at risk of getting oneshot in highest difficulty content. Same holds true for "random" magic damage that may be hitting you out of nowhere because you haven't played that specific content before and didn't know to Spell Reflect in advance. Other tanks have some fallbacks like Cheat Deaths, passive 20% magic reduction, much bigger health pool. Being at risk of getting oneshot / spiking hard is exactly the opposite of what you want from a tank. The new changes push the spec even more in that direction of being really OP during Ignore Pain, Shield Block but really at risk when it's not up. I regard it as a really bad sign that Blizzard doesn't understand that and pushes towards it and not away from it by stuffing all our survivability into even shorter Shield Block uptime and an Ignore Pain version that needs perfect timing and is probably too costly to sustain for high constant damage unlike the current version (which can be used for that because our rage gen scales with dmg income!).
And as I described in my image, if we'll turn out to be spamming Ignore Pain it's either totally OP if it never empties our rage bar because we can generate enough rage to never drop it (unlikely) or if it constantly drains our rage bar, it will feel really clunky to use any other abilities (especially Shield Block) when you're getting drained to 0 rage all the time. Maybe we'll be able to toggle Ignore pain on/off if we decide we'll need the rage for something else but honestly the thought of having to constantly toggle an ability on/off while fighting to prevent being resource starved (that's a terribly unfun feeling) makes me puke.