It might give some people ideas about the continued usefulness of pre-dreadnoughts.
The bigger impact IMO is that the Russian Black Sea Fleet is now capable of far more aggressive actions. There were talks of the Russians conducting an operation in support of the Entente operations in the Bosphorus in OTL, perhaps they move further in TTL. If the Russian Black Sea fleet attempts to support Churchill's naval attack in February, I don't think it changes that much militarily, but the diplomatic impact of such a possibility is intriguing. In OTL there were frantic attempts in late 1914/15 to build a Balkan coalition to support Serbia, depending on who you read, Bulgaria could have gone either way. The dominance of the Russian Black Sea Fleet following TTL's Battle of Cape Sarych might be enough to tip the scales in Bulgaria and have them join the Entente in order to prevent Russia from walking away with all the spoils from the impending collapse of the Ottoman Empire.
Bulgaria joining the Entente in 1915 basically guarantees an earlier Central Powers' defeat. Without the threat of Bulgaria on their southern border, Romania will attack Transylvania and Greece is going to get off the fence again to ensure that the Bulgarians don't take everything. It's also hard to see Italy remaining neutral as long as they did in OTL in such a scenario. Though I don't see the Turkish Army going down without a fight as they'll certainly give the Entente a run for their money in Eastern Thrace, I think that the Romanian invasion of Transylvania coupled with Allied aid pouring into Serbia might push the Habsburgs to the point of collapse, their diplomatic and military documents clearly state that they didn't think they could last in such a scenario. Even if the Germans allocate substantial troops to containing the Romanians and Serbia, the additional strain of a much more active front in the Southeast is going to accelerate the end of the war dramatically.