I tried to look at Meitetsu website surrounding the trains going in/out of NGO and based off the two URLs below:
??????????????????? - ??????? | ?????
?????????????????????????????? | ?????

Looks like as long as the train departing at the time has first class cabin cars, then they should have luggage racks. Mu-Sky Limited Express trains are all first class cabin cars (4 cars total), while Rapid Limit Express trains should always have one or two first class cabin cars plus regular cabin cars. Regular Limited Express trains might or might not have first class cabin cars. The NGO line only has Mu-Sky (every 30 minutes) and regular Limited Express trains (also every 30 minutes, 10 minutes after Mu-Sky) based off the schedule PDFS for trains departing NGO:
????????????????? (weekdays)
??????????????????? (weekends/holidays)

The first cabin cars have special surcharge (360 yen) on top of the train fare and you can reserve a seat. Hope that helps!