Based on previous discourse about the card system I think that you'll generally see a tendency towards blue cards in the first half when a red card might have been given before.

I think you're right, but I don't see it as a good thing

Referees have expressed a reluctance to show red early in the game, because an early red can seriously change the game in a way a late red doesn't.

That's not supposed to matter - it's either a red card offence or it isn't, regardless of the time on the clock. The ref is not there to ensure the match is entertaining or balanced. He or she is there to make sure the rules are followed consistently.

I think the blue cards will give referees more freedom to enforce the rules without completely changing the dynamic of the game, and as long as you don't actually believe the refs are conspiratorially disadvantaging any teams then this is a good thing.

It will give them more freedom, but IMO this will mean more inconsistency, as similar fouls are punished differently in the same game (for the reasons you suggest).