We have a new warehouse being built and your only option is the ceiling/roof mounting access points.
Assuming we use the MR72 are there flexible dipole antennas for these?
We are using MR46E with flexible antennas for warehouse.
As mentioned the MR46E is a good choice for warehouses. I have a number of customers that use them in high ceiling environments.
The MR72 went end of sale 5 years ago. Also, while you could use a modern outdoor AP inside a warehouse keep in mind it has different external antenna options and also the outdoor APs only carry a 1 year warranty vs. lifetime on the indoor models.
My only concern was the temperature requirements of a warehouse in Summer. Not sure indoor APs would be suitable.
Here are the MR46E environmental specs from the data sheet. No customers I have worked with have had a problem in a temperature controlled warehouse.
Another post provided a handy antenna chart for Meraki branded antennas that you might find helpful:
https://community.meraki.com/t5/Wireless-LAN/Meraki-Supported-Antenna-Chart/m-p/128264
If ceiling height is especially tall, using omni-directional antennas (like dipoles) can be problematic though especially if there is lots of high racking, at least in my experience.