There are multiple references online that state that the permitted output amount for OP_RETURN outputs is exactly zero satoshis:
Bitcoin Core 0.9.x to 0.10.x will, by default, relay and mine null data transactions with up to 40 bytes in a single data push and only one null data output that pays exactly 0 satoshis
[…]
Bitcoin Core 0.12.0 defaults to relaying and mining null data outputs with up to 83 bytes with any number of data pushes, provided the total byte limit is not exceeded. There must still only be a single null data output and it must still pay exactly 0 satoshis.
(emphasis mine)
However, I cannot find any indication that this restriction existed in any bitcoin version
The only policy-related effect of OP_RETURN transactions that I can see is that they have a different lower limit for nValue and permit values as low as 0.
Is there or was there any upper policy limit on the value of OP_RETURN outputs?
