Well, oracling MC is worth for Mack here (or other tech). Let me try explaining why:
1. Since everybody thinks Mack will go for Oracle (I'm guessing this because that was what I thought), it'll be easier to get a religion when going to priesthood. A religion is a very great boost for a non-creative Civ. Only popping a second city border is already a great help, because everybody hates monuments.
2. Most of the early game Wonders are tied to the religious line of the tech tree, so an IND civ has sinnergy by going that way, anyway.
3. Priesthood is a dead end tech when you don't plan to get the Oracle. Yeah, it opens monarchy and CoL, but it's not very common to need this techs in the early game (and you could go for Monotheism to get Monarchy), at least not before Math/currency. On the other hand, Sumeria has Ziggurats in priesthood, making it a more valuable tech on its own (I don't know if the maintenance will be harsh here, but it's a benefit anyway).
4. Oracle + priesthood (spiritual temples) open up the possibility of a Great Prophet for a early shrine. It's not easy to farm prophets late game and a shrine can be very helpful. Maybe you want a different GP for your first one, but there's flexibility here.
5. Forges are very good buildings when playing an IND civ, when they cost the same as a non-EXP granary. First, they are a happy building (especially in planned maps where metals are common - i don't know the map, just guessing from previous games). Second, there are cities that aren't worth building a library, but you want to build something while growing (or to overflow into something else), even very early in the game.
Besides, MC tends to be very delayed if not gained by Oracling. Only having the option to build forges is already a big boost. You don't need to build them in the 10t following the Oracling of MC, but 25t later, they might be a key build, which you wouldn't have access without the oracling.
6. With Mids + TGL banned, Colossus is a very good economical wonder. And there's coast already revealed (including a potential site to build it). No one can beat a IND civ that oracled MC to it.
7. With spiritual, you can time the civics change more freely. There's no need to worry about double-revolting civics and things like that. So even if you delay Monarchy, it's not that big of a deal. With ivory already revealed and two calendar resources, Monarchy can wait a good time, it seems. This ups the value of other techs.
8. Is this AW? Trirremes can be a lot fun against people that don't have MC
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9. MC is on the way to knigs :neenernee.
Of course, maybe other strategies are better here and some of the benefits above are tied only to the Oracle, not MC. But, I wanted to write a bit, so there you go.