It was officially declared

If they're able to setup a live ops team that's devoted to OSRS gold generating MTX related content and delivering stated content within a timeframe, why can't they upscale their center content team to deliver the same level of articles whilst retaining it inside the ETAs they cite to us.

You know why: cash. The fact of the matter is, major content updates require a shitload of effort and usually don't make a great deal of money. Comparatively, a small event with buyable currency doesn't require much work and brings into a shitload of cash.

Let us say it took a group of 10 (devs+artwork +QA+PM) about a month to create it (I can not imagine it taking a whole lot more than that). It costs about $40 in bonds to buy every one of the makeup, and that's not including leveling the artisan up, IDK how mathematics works out but skimming the amounts it would probably be at least double that, so let's say $80. That means only ~1000 players will need to cover this event for it to be rewarding, and that's not even such as the sharks who will purchase everything and a dozen of each of the consumables, or the many more that will set a couple of bonds into it but not go all-in.

It was officially declared about 3 weeks before launch, so you know that it was in development years prior to that. It attracted new assets, narrative development, etc.. Most likely this could have been multiple months of development having quite a large group, but just to show the point, let's say it costs precisely the same as the Artisan event to develop this exploration. Contrary to the previous case, it costs nothing for present members to participate this content. The only way that this makes money is if people return to the sport and resubscribe to play this. At $11/month for membership, you would need over 5000 players to resub for this to be rewarding. That is 5x the participation needed compared to some small MTX event, and this relies on bringing in new or bringing back returning subs - a thing considerably more difficult to perform than getting present users to spend a little extra.

At the end of the day, Jagex is a company, and if they want to keep the lights on, they then can not manage to dump buckets of cash into material which does not bring in revenue. I'm not saying that this is a justification to never develop new content - on the contrary, they have to keep the userbase participated or there will be nobody left to cover anything - but it will explain why monetized content seems to be prioritized and Cheap RS gold sent more exactly than other articles. As it stands right now, the MTX content is what funds the true content. As for me, I quite like the direction they're leaning of bringing in certain permanent improvement with every event, even though this first one was not a massive success.