I don't think you can attribute Shirley's lack of material this year to Linda Henry's hiatus, or SOC not being interested in her. Shirley hasn't really been used well for over a year now. She's another toy that DTC got bored with, and to be honest the rest has probably done her character some good. Now people are calling for Shirley to be used more, whereas before people were complaining she was being used too much, so that can only be a good thing.
But she really, really does need a decent storyline now. I don't think SOC is against the Carters at all; he's given them one of the biggest stories since he arrived in Lee's depression, as well as the first 'OMG' moment under his tenure. Linda and Mick feel revitalised under him, and Tina got some great development in the weeks leading up to Sonia's departure, though admittedly she's gone very quiet recently.
Hopefully SOC will continue giving the Carters the decent storylines he's started with them, and with there being less of them maybe Shirley (and Johnny) will get more of a focus next year.