The OpenPOWER Consortium was created in August 2013, more than three years after the RISC-V design effort started, but yes two years before the RISC-V Foundation was created and the then current ISA draft was widely publicised.
As far as I understand, at that point your only freedom was to license IBMs core or chip designs.
IBM released their first open source POWER core, the "Microwatt", in August 2019, a month after the base RISC-V 32/64 IMAFDC ISA was ratified (frozen forever and published)
The cores used in the highest performance RISC-V SoCs currently available were announced in October 2018 (SiFive U74) and July 2019 (THead C910).
I think OpenPOWER had some initial patent grant or license issues that wasn't ready until a few years after, after RISC-V came out. By then it was a little too late.
May be blame it on IBM again. Personally I quite like OpenPOWER.
As far as I understand, at that point your only freedom was to license IBMs core or chip designs.
IBM released their first open source POWER core, the "Microwatt", in August 2019, a month after the base RISC-V 32/64 IMAFDC ISA was ratified (frozen forever and published)
The cores used in the highest performance RISC-V SoCs currently available were announced in October 2018 (SiFive U74) and July 2019 (THead C910).