I could foresee a scenario when you RMA a failed Raid Array drive and it happen so that WD/Seagate decides to "upsize" your replacement drive to a bigger capacity, in that sense you won't get into any issues with Synology SHR by just slotting in the bigger capacity drive.
sometimes it could be some family member's naughty son/daughter visiting your home for CNY/family dinner and happen to see your nice little NAS and itch finger....
I keep it in my storeroom where my fiber point, wireless router are, and it is normally close.