Get the certificate now. You'll still be able to get another WT on Tuesday to complete before maintenance. You just won't be able to get a second one next week.

Quote Originally Posted by Jennah View Post
Chances are just doing the MSQ will get your first class to 90 with EXP to spare.
Anyone pushing MSQ at launch will be short XP at some point unless they do side content. I can remember doing a bit of side content so I could hit 79 and again to hit 80 so I could continue MSQ at Shadowbringer's launch. Just doing the role quests and Aether current quests hadn't been enough to bridge the gap. My alts didn't need the extra side content because I wasn't going through MSQ as quickly on them so had a lot of rested XP benefit while doing the dungeons.