No it won't. The only time I've heard about the letters coming off is due to the constant heat from the wireless charger. But otherwise the adhesive holds pretty well.
Sent from my Nexus 5 using Tapatalk
Nexus 5 - 32GB - D820 - latest 4.4.4 Mahdi ROM with Franco's Kernel
Sony Xperia Z Ultra - C6833 - White - Latest stock rom and kernel - rooted with Dual Recovery.