Q.What Would The Recommended Moisture And Ph Levels On A Plant Meter Be For The Following Plants:
Majesty Palm (Ravenea rivularis), Mass Cane (Dracaena Fragrans ‘Massangeana’) , Cordyline Fruticosa and a Dracaena Corn Palm.

Certified GKH Gardening Expert
All of these plants have similar requirements and care, fortunately. pH will be ideal in the "slightly acidic" range. 6-6.5 is idea, but they can tolerate neutral soil.
Moisture will fluctuate, if you want them to be healthy. It should go from saturated to almost dry, down to about 3 to 5 inches, which is where all of your beneficial bacterial will be. This is the important soil layer. You never want this layer to remain wet or dry, and it must fluctuate to be healthy.
Otherwise, here are some articles that will help:
https://www.gardeningknowhow.com/houseplants/majesty-palm/yellowing-majesty-palm-plants.htm
https://www.gardeningknowhow.com/houseplants/dracaena/how-to-grow-dracaena-corn-plant.htm
https://www.gardeningknowhow.com/houseplants/ti-plant/growing-hawaiian-ti-plant-indoors.htm