Exploration doesn’t change particularly that much over time, i have left and came back over the years and i don’t see great changes too it but i will try to fit you in what you need to know.
First drone sites got worse, a lot worse, because the price of drone capillary fluid dropped to almost worthless and since it was the reward you counted on most your income from, those sites are pretty much worthless now. Unless you like very infrequent payouts.
Wormholes decided to add a ton of new inter connecting wormholes in all wormhole systems, sure it was good for the high end but it really increased the difficulty for the low end ones and i am not aware of them fixing it too this date. Kind of ruined low end wormholes and i don’t believe they have fixed it yet even though they know its a problem.
I would look into understanding invasions and the dangers of some systems being Null inside Highsec.
I would also look into the market changes and new costs associated with editing your price which greatly effects exploration loot since it sells less frequently than say tech 2 loot.