Should I expect a new grade of Dark Matter in EW?

[Omedon]

Hello again.

This is my first time being present for a new expansion's transition and so there are a lot of truths I'm sure veterans take for granted that many like me won't know.

Today I want to ask about dark matter: Is there any point stocking up on grade 7? Will it still be useful from 80-90 for repairs according to precedents established?

I have no idea what prompts a new grade or if new grades happen, so I'm asking here.

Thanks in advance for any and all helpful replies!