I planted a Sego Palm too close to a sidewalk . After years of trimming, I finally cut off at ground level . The trunk was about 42" , so I dug a 36" hole and planted it. This happened last fall , the 5 big fronds are green and look healthy, but it did not put out any new growth ( New growth is in May for Zone 9). So I wonder if it skipped a year of growth or is dying ?
If you cut the palm at the ground level and then replanted it I would imagine it is probably in shock from having its entire root system removed. My guess is the reason you didn't see any new growth this year is because the plant put all of the effort into growing a new roots. I'm the kind of gardener that won't pull out a plant until its 100% dead so I would leave it where it is and see what happens next year. The fact that the original fronds are still green and healthy is a good sign. A layer of compost will likely help the plant recover from the transplant shock and give it the nutrient it needs for new roots/fronds. I've read that Sego Palms benefit from regular fertilizer applications but I would read up on this more to figure out how often, how much and specifically which nutrients benefit Sego Palms.