I'm more inclined to think that if there is a typo, it is earlier in the section which implies that you have to choose abilities in each speciality. An "option" to have a techmarine without mechanicus implants seems a bizarre notion.

But those same implants should not hand a +2 TB straight off the bat. A player with a techmarine in a game I'm currently in picked up bionic lungs...before becoming aware of the TB increase. Needless to say said player was down with that.

Anyone else miss how Technaribes get free bonus implants at certain ranks? I sure did.

The real question is wether or not it is intentional that a Techmarine gets a 'free master-crafted cybernetic' at the same time they have the renown to get a servo harness.

'Free Master Crafted Servo-Harness for all Famed Techmarines!'

Ouch, I'd missed the latter if not the former. Methinks a houserule barring a servo-harness is in order.

I don't consider servo-arms/harnesses true cybernetic implants. they're attached to the techmarine's power armor, not grafted permanently to his body. They're more like wargear than implants. Hence I would not allow that.