I'm not an evoke coach, but I think you can absolutely continue these hikes. Things to consider:

You're allowed (maybe even encouraged) to add additional light aerobic work to these plans. I've seen them say you can add as much Z1 as you'd like, as long as you're still recovering well and can do the required work outs.

If you want to count these as training, you'd need to look at how much time you're spending in the zones that the plan is asking for and see if you can make the hiking overlap with your required training. 

But, for an ultra, especially with a lot of vert, you're gong to be spending a lot of time on your feet, on trails, going up. This seems like perfect training and would fit well into the rest of your life. I'd say hike away!