Am I missing something here, or has this discussion ignored the fact that the Shimano 1x12 MTB drivetrain is intended for use with "boost" thru-hubs only, which are incompatible with most dedicated touring frames and bikes, which generally require 135mm x10mm QR rear hub. I cannot find any micro spline capable 135 QR Shimano hub. I don't think they make one or intended 1x12 for touring application.
DT and Hope seem to have either micro spline 135x10 QR hub (one in 36h!) or adapter freehub for older model hubs. In addition to having to spend ~$200 on a rear hub, you will have to order it (possibly with long wait), then have a custom rear wheel (wheelset if you want matching hubs/rims) made, or DIY.
If you are seriously considering SLX 1x12 drivetrain, be sure to factor in the cost of custom wheel ($350 +). Or a new frameset/bike with thru hub capability (Surly Troll comes to mind). I know that seems a little pricey, but bear in mind that 1x12s SLX means you do not need a front derailleur, gear shifter, double or triple crankset and 100cm of cable and housing - just think of the mechanical simplification and weight savings!