I don't mind this at all. I like seeing my shields at work. 

The Novalith should have no idea it's having no effect without recon.

Bombardment from close in though by siege frigates I guess would have them wondering though.

Star Wars: How can they be jamming us if they don't know we're coming?

Who knows. The siege frigates may be hoping to create a hole. Why shouldn't they try? Do they know that the planet is listed as invulnerable? Only a player would know that. But I guess that is what you want the AI playing like to an extent? A lot of players would not realise a planet is invulnerable and maybe this is the point.

I think half the point here is that the AI should perhaps not be as perfect as the perfect player. It needs to have built in flaws mistakes and personality traits. Sometimes an AI should NOT notice things like shields making a planet invulnerable.