Relic +1 gear is already obtainable (fill storage slip 07 with the GM moogle), so testing the upgrade process for +2 pieces will be possible.
Testing PUP isn't that hard to do; unlock it, set it to 95, and obtain all attachments/frames/etc. at the GM moogle, pull full Cirque +2 off slip 10, choose between Rev Fists +2 or the lv89 NM-drop weapons, grab an Animator +1 off slip 01. You aren't necessarily the world's best-geared PUP, but you have enough to test it.
The main reason for allowing relic weapons is (1) if they make some major change to them at 99 [in which case they'll probably put a specific NPC near the Magian Moogles, like they did for VW Phase 2 in Norg last testing phase] or (2) if they decide it's worth it as a means of attracting more people to test [in which case they'll probably also make mythics and full Empys available on the test server in the same way].
My personal opinion is that #2
is the case - the test server was sitting at single digits an hour or so ago - but this is one of those "it may bring more idiots than it's worth" situations.
That said,
if they decide to make relic weapons and the like easily accessible on the test server, I'd rather have an additional Magian Moogle that's like "Well, thanks to the help of some mysterious kind figures who supplied us with fairy powder, Poroggo leather, and unobtanium ingots, we can auto-complete any trial of your choice. In addition, you can trade me an incomplete relic or mythic weapon for the finished article." Give him a bright purple pom-pom, too.