Would there be a use case for this derivative?
This market is potentially (in a world with increased Bitcoin adoption) very big. One of the main applications I see is for people who get their salary in Bitcoin; which could then invest a big part of it for 30 days in a "moving average contract" to be sure the money wouldn't lose much in the course of the month until they get a new, "rebalanced" salary, but potentially profiting from a price increase. That would be a good alternative to change it to fiat or stablecoin, and it wouldn't leave the "bitcoin sphere" (potentially it even could be realized as a discreet log contract - see also this Spanish thread - with Bitcoin settlement so it doesn't even need to leave the blockchain, although this would not cover the case "Bitcoin goes to zero", which can only prevented with fiat settlement, but this cannot prevent that fiat goes to zero ).
The question is if the sellers side, i.e. the "shorters" (those guaranteeing the EMA price) have enough incentive to enter this market. If the market on the "long" side is big enough then they can compete for a potentially significant premium, although a too high premium will make the contract less attractive for the use case I described above (I think ~3-5% of the invested money is the most one would accept to pay for it, otherwise converting to fiat/stablecoin, or using a options collar, is much more attractive). I have to think about more use cases for them.