It cannot be a coincidence but hey CBoe was already providing the spot futures in ETH and in BTC and due to their outcomes, they thought to provide Margined futures in ETH and BTC. This will increase their traffic but I don't know how this is going to be beneficial in relation to ETFs, as if ETFs will be approved on Jan 10 2024 there are 90% chance that all other ETFs including Block Rock's will also be approved.

Then why would people prefer to use the Cboe platform to do margined trading in BTC or ETH? As margin trading and spot trading are two different things in both you are buying BTC (taking position) and if ETFs get approved then BTC's price will increase which as a result increases the profit of those who took positions on the Cboe platform. The demand for BTC might increase among those who are traditional traders and want to buy BTC from a centralized (way more) platform.