Yes. And top that off with Jon's death not being in the epilogue (or prologue) which is the only time GRRM has killed an active POV character....
None of it is proof. But it certainly is an indication. And GRRM is good about showing a power being used on a minor character before he uses it on a major one. It helps the reader ease into the fantasticness of it all. Think Jaquen, Thoras, the various prophecies, Aryas training catching the Tom cat, Varamir, etc.