1. Does WoW need a new class for 10.0? In other words, do you feel that the lack of a new class in this expansion hurt the game, and another expansion without a new class would hurt the game further?
Yes, it does. Far too many races were introduced to the game, which was a big mistake because it heavily burdens the artwork team. Like you said, we have not had any new class in several years. We need a strong, versatile class who can fulfill all roles and will appeal to the general public and not juswt a small group of persons.
2. Do you think a new class in Shadowlands would have made this expansion better/more interesting?
Yes it would have. So far, no new races and no new classes were introduced in SL. This is only the 2nd expansion in the history of WoW that no new race or class was introduced. It would have provided valuable and entertaining content for players.
3. If there is NO new class introduced in 10.0, will that effect your purchase of the next expansion?
Probably not. I will buy it because I am a loyal player, but it will definitely affect my opinion of the expansion.