Hi Mike,
Melita answered this a month ago. Not too late I hope.
Alaska is the same as CONUS on these transformations. We also are in the same epoch of NAD83 as lower 48 in the eyes of NGS. Our geoid models are all Alaskan-grown and are getting quite good. Only some datum transforms "transform" or "shift", or "tweak". Melita mentions the null transform or what ESRI calls Bookkeeping transform. Those are found throughout the composite and singular shifter list. These are necessary at times to use. A null transform doesn't move the data at all, merely re-defines. Others do shift. Many shifts are very, very small, under decimter, some under 1 cm.
All the SDMI Spot /IFSAR data is tied to the NAD83 (CORS96) Epoch 2003.0 reference frame. So, we in Alaska have been in modern variants of NAD83 for some time.
Your getting GIS data assigned with the NAD83 (2011) likely from those who are aligning GPS data to CORS and aligning them more specifically to the latest reference frame of NAD83. It will pay in the future when the new realization or datum is rolled out in 2022 to very precisely defining the data we sit on. This reference frame is going to be likely with us until around 2022. Its only appropriate to apply shifters to/from NAD83 (2011) for data that really "is" in that frame.
I tell folks to test these yourself. Learn what the single transforms do, then build up into using composite transforms.
Which version of NAD83 is assumed in geographic transformation?