Cut offs this year would predominantly be staying in the 450s not in the 470s if they continue with 3350 ITAs. Today's was an anomaly due to the 4 week gap draw.
The number of applicants have been increasing each year as Canada has become the most favored destination for immigrants in the last few years. So, cut offs could go higher even with 3350 ITAs but maybe into 460s in the next 2 years if the influx increases.
490 cut off is only possible if they decrease the number of ITAs significantly, which does not seem like an option now with the targets but you would want to keep a close look out on the after election situation before concluding anything as targets can be changed.
Also, 2021 is not the last year of EE, the targets have been set till 2021 as of now. There is no plans as of now to discontinue EE.