This is a virtual world, not reality. There's no actual die or spinning wheel that follow the laws of physics. The payoff is whatever the programmer wants it to be, just like the electronic slots in Las Vegas.
From observation it seems to me this game is giving away more "consumable" items like instants and buildings that have limited life spans. I think it's fairly obvious items of value like sectors and excellent buildings are being rationed to prolong the money earning lifespan of Elvenar. Doesn't mean it's no fun to play, just that Events are less rewarding and if you want the good stuff, bring diamonds.
I am not sure how the first quote relates to the second, even though they are from the same paragraph. First, yes, a simulation of randomness is being used, as true randomness is impossible to obtain, but that does not mean the simulation is any further off from a random outcome than a die roll.
For the second statement, yes, a rationing is going on by making less of the pure culture available and placing more consumables in the standard offering. This does not mean that it is less likely to get a permanent on its day than a consumable on its day. Rather, before we had an offering of nearly all pure culture and population and culture, and now we have many other new productions added on.
As anecdotal evidence seems to be what is in vogue for offering "verified" conclusions, let me enter my anecdotal evidence which runs against the grain of the random number being tinkered to ration. Going through this event without spending diamonds, I was able to obtain 6 shrines of Kirit and 10 shrines of Krarak, giving myself a total of 16 dailies in about 150 chest openings (1 in 17 chance of doing that well or better). When I spent over 500 splinters for the consumable trading outpost the next day, I got zero and used up all my splinters. The good anecdotes like this are often the ones not spoken about, and the bad luck ones (like jps' 2100 splinter investment that returned nothing, a 1 in 400 chance) are touted immensely which often causes the "verification" to run towards bad luck, as that is what is being discussed the most.