The problem isn't with what they "Can" or "Can't" do, but with what they
Want to do.
TCW was a very expensive show. GL didn't mind, as his deep pockets gave him the freedom to "tell stories" has he saw fit. He didn't answer to anyone and it was all his money. So if TCW cost a lot, but it was still what he wanted to do, then he'd do it. And he did just that. TCW was going to be a big Star Wars hit and this was going to pay for itself, just like all other SW properties had. The TCW Movie, then the TV show, and then the toys, and then the associated merchandising. Plus there was a 5 year commitment, so the show would be in syndication worldwide for years. In America, TCW was shown not only the kid oriented Cartoon Network, but was also shown on the Adult Drama oriented (Turner Sister network) TNT channel.
But not everything was that successful. The TCW movie was a box office disappointment by SW standards, that TNT channel showing only lasted a few episodes, and Cartoon network moved the time of the show around a few times trying to find a optimal audience. The show never did find its way into syndication, and when Disney bought up SW, they didn't want their new property on a Turner owned network. I'm sure Turner that the TV rights to the show, so they couldn't move TCW to Disney XD, so they just axed it immediately. Luckily streaming was available.
Disney thinks about TV in a different way. We go that with Rebels. When season one Rebels started, there was a lot of new requirements for the new Disney show. Each episode was going to stand alone, all shows would take place in a single location, each episde would follow just a single set of characters, etc... Essentially, what was being said was "These episodes are going to be cost conscientious , and could be thrown into a DisneyXD line up out of order at any point in time." I"m sure Filoni and team were like "Yeah, we can totally do that......... No arcs, no problem. he he". As Rebels took root, we began to see them return to the TCW ways were the last season was pretty much all arcs.

(Which I personally prefer)
So what does this all tell us about Disney's mentality when it comes to the TCW revival? Well sadly, from what I have seen so far, it is that Disney is only partially vested in this. They have a new streaming service that they want to launch and they need a few anchors that are exclusive to this to get people to sign up. We all already have Netflix, most also already have Amazon Prime. Do we need a third or forth? Nope. In order to get us to sign up, they better have some good material. So when they went around the table to their properties and asked "What have you go to offer quickly?", the SW folks were likely, well, in 3 years we can have this or that. But hey, we go this TCW stuff that is already 1. Written. 2. Voice Acted. 3. Story board animated. 4. Sound Work already done. 5. Fan base already well established. All we need to do it pick up where it was left off, send the stuff to Asia for final animation we can have it done by launch time, since there is already a year head start on this stuff. Bad new is that we only have half a season of episodes done. I'm sure Disney said "Hey that's good enough". Green Light!!
So I am very glad to see that more TCW is coming. But I see this more as a cleaning up and getting out the rest of season six, rather than show coming back. I do not know how much of these new episode are going to be season six and how many are going to be fresh. My hunch/intuition says that we will see those TCW Legacy rough animation episodes (Bad Batch ARCs, and Utapau Crystal) and the siege of Mandalore. Those could nearly take up all 12 episodes themselves, so I'm not sure which of the many other revealed stories could make it in this new streaming season.
For me the sad news of this, is that in the trailer when we see Ahsoka return, that to me confirms that the Siege of Mandalore is here in Season 12. Also from what I have read, this is when Ashoka and Rex head off to Mandalore to fight Maul, while Anakin and OBI speed off to rescue Palpatine from Grievous beginning ROTS. So in other words, this gives us perfect, permanent closure to TCW. So once this is done, we will never see any hope of a new TCW episodes again. This is IT, the true end.
So while Disney can do what they want now, the problem is that what they want is to get some cheap last minute TCW stuff to us to prop up the streaming service and then to put this show to bed forever. Happy for more TCW, sad to know that this really is the end this time.