Ocean life and coral reefs are in danger due to temperature rise as a part of climate change. Energy efficiency helps reduce that temperature rise.
There isn't an "increased demand in datacenters" just because datacenters are more efficient. There's still the same demand, but it can now be met more efficiently.
If the process was not as efficient, you would still attempt to meet the demand, except that you're producing more waste (waste heat especially in this case), over a longer period of time.
Waste is waste, reducing it is never a negative.
People need services and data centers are how they get them. If data centers are expensive then I invest in efficiency work because 3 FTEs are cheaper than 2 additional data centers. If the centers are cheaper I will just burn watts to solve my problem, and spend those employees on something else.
And we were talking about whether we should, not whether we can. “Demand” can be a lot of things. Demand is not a justification.
If we wanted to accelerate climate change, we could obviously do so (as proven in the last century). Meaning we have an impact on the acceleration of climate change. Meaning we can make decisions to make that acceleration slower, rather than faster.