This has me thinking...

my guess is that for this runway change, the 18s/36s at TPA must have had a magnetic heading of 184/004, not to exceed 184.5/004.5. If so, and the magnetic variation from the N. pole caused it to roll over .5, then any airport near that threshold is going to have that same issue.. so at least in N. America, I'd except every airport with this situation to change runway designations. For example, KSAT and KRNO could change, since they are close to that threshold (KSAT has 12R/30L at 126.5/306.5 magnetic, while KRNO is at 184.3/344.3 magnetic).

Don't know for sure..

BL.

You are on the right track. In the mid 2000's the Rwy orientation was 185/005. It is estimated to  change by +.1 degree west per year since then. Right now the orientation is 006.5.