We cnnot say 100% that altcoin season started, only future will show, but indeed it's a good sign that ripple awakened. I personally think next altcoin season begins with ripple.
This is not the start of the altcoin season, we need to wait longer. When altcoin season start it will be on every news around the world, and that will be after BTC hits new ATH. When will that happen is hard to say, maybe next year, or in 2021, if we are lucky we will not have to wait longer than that.
I`m sure that next altcoin season will not start with ripple, it`s crazy to think that.