well, it's most definitely on the later side of things, but with life, there really are no hard and fast rules. As long as the mycelium stay healthy/avoid contamination, they should live just like any other organism. They require food, water, and light (to signal fruiting). The cakes are providing them the nutrients (food) they need, so until they use up all the nutrients, that won't be an issue, and you control water (humidity) and exposure to light (like 12ish hours/day).
There are thousands upon thousands of seeds buried in any square foot of soil that don't germinate and grow because the conditions are not right to initiate such growth. If you take a soil sample you will find an exponentially greater amount of seeds than could ever spring to life at the same time in that given patch of land, instead the different ones gorw when the right conditions are present. Similarly, your cakes are essentially in a dormant state and are waiting for that water trigger to initiate the next stage of growth.
It IS possible that they have completely stalled or otherwise will not fruit, but A) if this were the case they'd be attacked by molds/contaminants and B) There's no reason to not find out if they'll still fruit, unless your water is really at a premium, :lol: haha, they're not gonna harm anything and it's always fun to see what nature/life can do. Besides if they do get contaminated, you can always chuck 'em into the woods/compost pile and see what happens, or just throw them away and you still won't have lost anything from where you are right now.