Unless you are buying an inventory car, you have no concrete date on when that car will be delivered, just some hand waiving of a future date which is fluid to say the least. Tesla realized that this uncertainty could cause some problems with people suddenly being told of a delivery while on vacation or not having their financing in place for that date, so they can offer up an exception to delay the delivery to accommodate buyers in those situations. But trying to exploit Tesla's good faith gesture and extending delivery beyond these circumstances is not something Tesla has to honor. They might have done that before, does not mean that they have to keep on doing that indefinitely. They are running a business and have to answer to shareholders, it is their responsibility to sell as many cars as fast as they can to increase their profitability and stock price.
You placed an order for car, you signed a contract to do so. Tesla is holding up their end of the deal and the car you agreed to buy is now ready. If the buyer is not willing to accept delivery at that time or beyond the small delay Tesla has allowed to accommodate issues like on vacation or to get financing in place, then they have no obligation to keep on extending that delivery just because the buyer wants to double dip or it is not convenient for them. Sorry, an order was placed and it is now ready. Give me one example of another other vendor who will keep your yet unpaid ordered item around indefinitely waiting for you decide when to pick it up, at the same price it was when you placed that order.
So what if Tesla implemented a third option here.
If you want to delay the order you placed beyond some grace period that Tesla has created to deal with people on vacation or trying to get financing in place, then the price is no longer locked to that original date the contract was effectively signed by the potential buyer and it slides. You get one 30 day extension but that comes with the caveat that you also accept the price 30 days after you placed your order. So if you placed your order just before a price increase, sorry, but now the price has just gone up. You only get one delay, then you forfeit your order, up to Tesla to refund your deposit or not. They fulfilled their end of the deal, the car you ordered is ready. If you are not taking delivery, then you are the one breaking the contract.
I know those trying to double dip on locked in price and potential EV rebates are not going to like it, but they should put themselves in Tesla's shoes. It's okay to expect the price when the order was placed if the seller is unable to deliver product at that time, i.e. not an inventory car. But by any reasonable expectation, once you submit an order for a new car, you want to buy it now. And once that supply bottleneck has been resolved and your ordered car is ready, then they are delivering what you requested. Tesla owes you nothing.