Jammin Jars is a slightly different case. It's more of a bag of results or a scratch card. So there is a pool of 1.2 million results and when you hit spin, it picks one of them and shows it to you. It's still a random game though, as those 1.2 million possible results average out to the stated RTP, and your chance of getting any one of them is 1 in 1.2 million.
For the majority of slots, the positions on the reels are what determine the outcome. Now, it is common that a game will determine all of the result up front (even the bonus round) as soon as you click the spin button. That's pretty standard practice actually (tho providers like BTG do hit the RNG for every single bonus spin). There is nothing wrong with this. Each spin is still the result of the reel positions generated by RNG for that spin.
You have to remember that, in almost all slots, a 'Spin' is defined as the point at you click the spin button to the point your total winnings are displayed and paid to you. This means 1 base spin and 50 free spins is all one 'spin'.
So in the coin flip example, if you were given 5 free spins on the coin, it would be like me doing 5 flips and recording a video of me doing them, then coming out and showing you the video. I still did 5 coin flips, they were still random, but the result was fully determined before you started watching.
Pre-determined does NOT mean rigged. Pre-determined results is absolutely fine, as long as it is done after you click spin, or, like Jammin Jars, it's a random selection from a pool of pre-generated results (although I hate Jammin Jars for this reason).
Slots simply aren't 'programmed' to achieve a target. They don't need to be. The maths does it for them through volume of play.
The simple fact is, you can't tell when a game is 'hot or cold'. You think you can, but you can't. If you could, you would be a millionaire because you would always win.
In a random set, it's very common to have 'hot' or 'cold' streaks within it. That is the nature of randomness.