Bulgaria’s Defence Ministry held a procurement procedure from September 2020 to July 2022 for a company to repair and maintain the S-300 systems.
Only one candidate was admitted, Almaz-Antey Aerospace Defense Concern, which is owned by the Russian state. However, it turned out that it did not have the ability to keep the missile systems in working order.
“Unserviceable” in this case doesn’t mean the missile systems aren’t working, but that future maintenance is going to be a problem because Bulgaria doesn’t have the technicians and supplies to keep them in working order up to military standards.
So yes, Ukraine would be getting functional S-300 systems.
The equivalent of milk the day of expiry. Sure, it can be used now, but if you aren’t gonna use it up today, you don’t want it hanging around. Ukrainian neighbor is making a fine victory cake today, though, so why not give it to them?
And nobody in Bulgaria came to the very obvious solution? Hiring Ukrainian technicians to keep them in working order many years ago. Or giving some to Ukraine for such a maintenance contract for remaining ones more than 1½ years ago.
From the article it seems like it isn’t worth the effort to try to maintain them in Bulgaria. Safety of the Bulgarian soldiers is important. Ukraine has greater expertise with these, and is willing to use them on the battlefield. Bulgaria is a NATO member. The same money spent on trying to keep S300 up and running could be spent on much better, more modern, safer, more effective weapon systems.