It's ITK, fella............but not exclusive to me!
There have been a number of articles on the official site over the past few years which have stated that the training ground pitch will have the same dimensions as the stadium pitch.
I realise that, I've visited both the current and new training ground sites, and have (with others) mentioned in this thread that lots, if not most top teams are doing it.
My comment was more related to the post discussing the impact of size of pitch at the new stadium vs training, and probably misreading the bit about the players will have been using it at the training ground for years.
Will it be as easy repainting the lines on the training ground desso pitch? I don't know, but I wouldn't assume things have been planned that far ahead. The distance between pitches and landscaping/natural drainage may not be able to incorporate those extra few metres.... but then again maybe they will.
Also, a new generation of pitch technology may have been developed by the time the new stadium opens in which case I would guess that we'd be installing that at the training ground as well.