If existing members do NOT take part
1) The whole idea of the election may chance .. now instead of fight for your oshimen .. it may be fighting for a purpose you find most meaningful ..
2) It would be a huge talking point ... making everything more interesting ...
3) Not taking part may not be bad as you may get people attention by not taking part ...
The members not taking part may in fact see a boost, but I wonder about its sustainability. Like it or not, I think the election is the ultimate in exposure and opportunity, next to management getting about 15 primetime TV specials dedicated to you i.e. Paruru. Passing up on that if you're someone who CAN make the election would be a mistake in my opinion.
But for a lot of members, it might be a risk worth taking if they're smart enough to figure out a way to make it work in their advantage. Kind of like going overseas for Mariyannu, I think it'd have a member who's unpopular in hopes that other unpopular girls don't follow the same trend. It could work, but it could easily backfire and have absolutely no effect.
As for #1, I can only speak for myself, but if my oshimen isn't involved, I'm not going to vote. I'm fairly certain she will be so that certainly won't be a problem for me, but I think "fighting for a purpose" is meaningless if your oshimen isn't that purpose. This isn't Request Hour where I can make a stand for SDN48 one year and Team 4 the next. I have no place voting for Ricchan in place of my oshimen as much as I like her and want to see her make the election this year. That should be Ricchan oshis' fight, not mine.