is it true that...

Obviously they do their research. They won’t base it off anything until they meet you, but they want to know background stuff. Fraternities do the same thing

There is no such thing as a Bid List until after Pref. The term 'bid list' gets thrown around way too much on here. It is a very different thing from a pre-recruitment 'list' of PNM's a sorority is very interested in. This interest stems mostly from connections that actives have to certain girls who they either know personally or know of through mutual contacts or places/things they have in common. As stated above, we need to meet everyone in person. NOTHING MEANS ANYTHING UNTIL RECRUITMENT. We may not like them, they may not like us. That's why we have recruitment week.

Yes pretty much every sorority has a list of girls they know they want.
That list varies depending on sorority. KD, for instance takes pretty much all their girls from their hoemtown’s/high schools in Alabama.
All sororities have a list right now of girls they prioritize who they know well, know through mutual friends, etc.
some sororities have more like KD, Chi O, Phi Mu for example.
Sororities like phi mu, Pi phi, zeta might be after a certain “look” and their list reflects what they want. And Alpha Gam and AOPi might have girls with very high GPA’s on their lists for example. So all 18 of the sororities are looking for different things because each one is unique and you want girls who are similar to you.
These lists are for the sororities to try a little harder when recruiting these girls on their lists so that they definitely are able to recruit at least a few girls who blend well with their sorority and the type of girls who make up that sorority.

Many sororities will have the same girls on their “top 100” lists. It is usually well known, involved girls from their high schools that they think would be a good fit for their chapter. So if a pnm is on multiple lists she can only pick one house. Most sororities only get 20 to 30 people on their list because they realize the girl would actually not be a good fit or because she chose to go elsewhere..

People who don't understand recruitment and MS like to blow this out of proportion. Just think about how many girls rush each year; how would you keep all those girls straight if you didn't research them beforehand? You only get to talk to these girls (on both the PNM and active side) for a few hours all together, so you want to know as much as possible to make an educated decision. You compile that info based on recommendations, her resume, who in the house knows her, if she's a legacy, etc. My house is one of those listed above that does this but just because a girl is on this "target list" doesn't mean that list and her position on it isn't subject to change. A PNM could fall in love with a totally different house, or actives could get wowed by a girl from far OOS. I'm from New England and ended up in a house everyone says is traditionally Alabama-centric. Don't let things like lists scare you because it's 50% misconception and 50% out of your control anyway. Just focus on what you can control and be happy wherever you end up!