I don't know if he will do it, but I am very doubtful anyone but him would write it. Were already past 25 volumes, theres enough chapters now for 26 volumes (so the old "no more than 25 vol's" stuff is no longer true) and theres still more to come.
but it´s not like we don´t have something else to look forward to...
Like a reboot of the anime for example.
I'm still highly doubtful that claymore will receive it, While we may all love claymore, the sales don't compare to other series who have had a reboot. (hellsing, hunter x hunter , full metal alchemist)