Perhaps he got a better deal on it buying now that he couldn't get in a few months time. There are plenty of reasons someone might do this.
Your fluids will be fine, don't worry about them. How long are you storing the bike? It should be fine without stands for a few months. Tires nowadays don't develop flat spots as quickly or easily as they did in the past, which is why people would raise the bike during storage or rotate the tires if on the kickstand. Personally, unless its a pitbull or other high quality stand, I'd be more worried about the stand failing after 6 months of continuous lifting and having the bike fall than my tires developing flat spots. I left mine on the kickstand from Jan-March and it was 100% ok.
I'm looking to store it for 3-4 months. It's a pitbull stand, I was prepared to dump my money on this hobby lmao! I got a full system akrapovic racing gp exhaust coming in soon. I'm so excited, I should probably go buy a legitimate torque wrench for the install.
He said he has a battery tender for it, which is a trickle charger.

No need to remove the battery, or the seat for that matter. Our bikes come stock with a connector w/ leads already attached to the battery (or at least mine did). Its zipped to the frame near the seat on the left side of the bike. I can take a pic later if need be, but you can just plug the tender into that connector and BOOM, charging.