Modern Swedish battleships as Baltic fire support

What would three modern Swedish ships with eight 15-inch guns and railgun secondaries mean for Baltic strategy?

The imagined ships would provide NATO with heavy shore-bombardment capacity and give Russia reason to consider their reach around the Baltic.

The hypothetical Swedish force consists of three ships, each carrying eight modern 15-inch guns and railgun secondaries. NATO would assign them a shore-bombardment role in the scenario. Their heavy artillery would also cause Russia to consider what Sweden intended to do with that capability around the Baltic. The suggestion of an attack on St Petersburg is banter about the imagined ships rather than an identified operational plan.