That James T. Kirk's father was George Samuel Kirk the Elder, and his mother was named Winona was established in FF and BD long before the first Abramsverse movie made it canonical (much the same as Sulu's first name was established in The Entropy Effect long before it was made canonical in ST5:TFF), and while only the names (and indeed, only "George" and "Winona"; not the middle name of "Samuel," nor the nickname of "Geordie," though they weren't actually contradicted) were actually made canonical, certain other central points originating in those two books had at least stood without any actual contradiction:
1. James T. Kirk grew up on a farm in Iowa (prior to FF, we'd known about Iowa, but not about the farm).
2. "Geordie" Kirk was career Starfleet, like his son, and was, for at least a portion of Kirk's childhood, an absentee father, with the two communicating via handwritten letters.
3. Winona Kirk ran the family farm during the period in #2.
4. Towards the end of the period in which he grew up with an absentee father, and as a result of what he witnessed on Tarsus IV, James T. Kirk teetered, at age 16, on the edge of juvenile delinquency, and wanted absolutely nothing to do with space travel.
Most of what, in FF and BD, has since been contradicted was in the realm of details: important to the plots of the novels, but not central to their themes, and not major continuity issues. These four issues are central to the novels' themes, and are major continuity issues. (And indeed, I would say that the fact that "Geordie" Kirk was not merely absentee, but deceased in the Abramsverse is the obvious explanation for the Abramsverse James T. Kirk having not merely teetered on the edge of juvenile delinquency, but fallen into it.)
I don't have a particularly high standard of continuity; that's how I can regard TOS, TAS, TNG, DS9, Voy, Ent, all prime-universe movies, and every prime universe novel all the way back to Spock Must Die and Mission to Horatius as being "the same continuity," but completely inverting major elements of the established (if non-canonical) backstory of Kirk's childhood breaks even my standard of continuity.
Understand, I don't regard this as revisionism in the same category as the unspeakable things that were done to Baum's Oz (starting with Langley, Ryerson, and Woolf, continuing with Philip Jose Farmer, through to Gregory Maguire). Neither do I, based on what little I've read so far (I was going to wait a bit longer, but last night, I didn't want to break out a magazine, nor go out to my car to retrieve the literary magazine I'd started reading this week) classify the present opus in the category of "unspeakably vile waste of paper" that I reserve for Gillebaard's Moon Hoax (nor even in the same category as The Starless World, World Without End, Perry's Planet or the ever-popular Devil World, which I regard as the four worst Bantam ST novels).
It just seems like a pointless breach of four major never-before-contradicted continuity elements that have had significant influences on canon.
