It doesn't make the FCC testing weird at all. As was said, it is unlikely this phone will be picked up by any carrier in the USA and be subsidized. It's more likely given SE's track record to release a NAM 3G (850/1900) which will work with At&t only. This is pretty evident by the fact Roger's is picking up the phone in Canada. They use the same frequencies as At&t. Making this phone a lot easier to get on At&t unlocked.
As for FCC testing, the FCC tests every GSM phone made that has any spectrum support for networks in the USA. This is because people traveling to the USA from other countries might have the phone and the FCC needs to approve of it. So not weird at all, it happens all the time. Pretty much any phone released in the UK goes through FCC testing here.
As for the tmobile bands, it was hinted at when this phone was originally announced that a version with tmobile capable 3G bands was going to be made, but not for a US release, but rather a South American release on some shitty little wireless provider in Brazil which uses the same 3G bands. This could mean 2 things. 1. The phone goes to that carrier locked, branded, subsidized whatever and importing might not work so well. 2. It will simply be an unlocked smartphone picked up by that carrier making importing easy.
