No clear answer here, as best I can tell. Western Digital "green" drives, which include the model you mention as well as their 3 TB WD30EZRS drives have a "feature" that parks the drive heads and turns off some of the electronics, to reduce power consumption. Each time the heads are parked, the LCC increases; the LCC count on a drive can be read by looking at the SMART status (on the health page of a Readynas). I believe LCC stands for "load cycle count" but I don't know exactly what that means.
When I asked WD support about this, I was told not to worry, the drives are designed to function with high LCC's, and this shouldn't cause the drive to fail. But there was more. The drives had been tested with an LCC of up to one million, but apparently not beyond this. Further, the WD green drives are designed for a desktop PC installation, NOT for a RAID system like a readynas. Western Digital would offer no guarantees when a WD green drive was installed in a RAID-based NAS.
I bought an Ultra 6 plus, and installed 3 WD30EZRS drives. And, I watched the LCC count. After 3 months it was at 250,000. So, it would hit the million mark in a year. I concluded this was not good.
There is a way to stop the LCC from increasing, which is well described in this forum and elsewhere: run a WD provided utility called WDIDLE3, which will reset the idle timer setting on the drive. Once this is done, the LCC will basically stop increasing (and I would guess power consumption on the drive will increase)
WDIDLE3 is easy to use, instructions are elsewhere in this forum, but it must be run by installing the drive in a PC with a SATA interface that can boot DOS (or freedos) from a CD or USB.
Once the LCC on my drives hit 250,000 I ran WDIDLE3 on them.
Now, the WD drives are on the Readynas official hardware compatibility list. So, netgear is treating them like they are OK. But the LCC issue is worrisome, and most forum users who have voiced an opinion run WDIDLE3.
My recommendation: either run WDIDLE3 on WD green drives, or use a different brand of drive (when I purchased my system, the WD's were the only 3 TB drives I could get my hands on). There are several brands of 2TB and 3TB drives on the compatibility list that don't have the LCC issue.