Will there be again a pre-purchase option/kickstarter support for the expansion? I remember wanting to upgrade my support to get the expansion included, but the billing system just wouldn’t support it.
Pre-purchase maybe, but I doubt another Kickstarter. The first expansion was included in most of the tiers for the Kickstarter. Why couldn’t you upgrade? I did it when the Kickstarter came out and so did a lot of other people who’d supported Crate pre-Kickstarter.
I supported post kickstarter and I contacted Crate support later to upgrade and they simply couldn’t.
Guess you’ll have to hope for a pre-purchase option then. 
Did you buy your copy of the game off here ? If so then it’s Humble Bundle that you need to contact regards upgrading to the Loyalist.
For a while there was no mechanism in place to be able to do upgrades, but afaik that was all sorted quite a while ago and it’s still going.
Hope this might help
okay. willt ry