This could be a game changer for seasonal energy storage if it allows round trip efficiencies of even say 60%. Ammonia has been demonstrated as a fuel in existing natural gas turbines [1] at combustion efficiencies up to 99%.
First you want to displace natural gas for fertilizer production. But yes, if the energy efficiency is good enough and the electrolyzer costs are very low, it would make more sense than electrolyzing hydrogen and then running that through Haber-Bosch. Remains to be seen if either of those criteria can be met.
Undoubtedly, at the scales needed for seasonal energy storage, containment systems with multiple fail-safes would be needed. But if we can do that for nuclear reactors, it's got to be strictly simpler for ammonia.