Perhaps it is me that is just not getting this.
The game is obviously confused on what it thinks a Jedi Consular is. When I am Consular/Defense Guardian my character sheet displays consular, and I can still use Consular phases. I cannot use Knight phases. I can only assume that my storyline would remain consular. When it comes to items, the reverse is true. The game believes I am a Jedi Knight.
To be clear:
Jedi Consular is an origin story. This is clearly established I believe.
Changing combat style does indeed change origin story, as evidenced by the character no longer being able to equip items that require Jedi Consular.
If both of the above statements are true, then the problem and therefore solution seems clearly defined.
There are at least 2 options for a fix that straightens out the issue:
1) Origin stories need to be modified to show that they are dependent on combat style, in order to clarify to new players that selecting a second combat style will bring this change in origin story (it would seem like a lot of other warnings may need to be considered as well)
2) Remove the relationship of combat style to origin story altogether. There is no useful reason to have it anymore, as any force user origin story can be any force user combat style. Any item requirements can simply be shifted to require either a specific combat style or force/tech.