There's 2 issues with that outcome...
#1. The CBA explicitly provides for the timelines under which a contract can be bought out... it's now, and for the next few days, IIRC. Presumably, Lombardi cannot file buyout paperwork, as there is no more contract to buy out in his view of the facts. Either a special exemption would have to be provided by the NHL (and PA) to allow a buyout during other times, or for them to agree that they can file the paperwork as "backup" now / retroactively.
From a PA perspective, I see issues with both... one of the reason(s) why buyouts are restricted to this time period, is so that bought out players then have the opportunity to participate in the market with all other free agents for spots, as opposed to the end of the summer when that player would be stuck trying to squeeze on whatever few teams have space.
#2. As far as we know, a buyout was not the next best alternative for Dean Lombardi. Apparently, he was talking to Edmonton & Calgary about a trade. Obviously, nothing was done, but we could reasonably assume that the Kings weren't in fact prepared to buy him out, but would've kept his contract in tact and traded him.