Stat weights vary from fight to fight but the general guideline is the following:
Since BfA has a lot damage that come from autoattacks defensively you want pretty much
iLvl > mastery > versa = crit > haste
Offensively it depends on your current gear but it’s pretty much
Agi > crit > versa = mastery > haste
Overall the difference between the top 3 stats isnt that big, so since you equip the highest ilvl gear you have you might end up with high crit or high versa. Or they want to gear more towards magic dmg where versa and crit are better than mastery. What matters way more is that how you play.