I was reading an article on another website about seedling apple trees. It stated that a seedling apple could bear fruit as soon as 3 to 4 years, but that it might take another few years before the fruit is edible. I thought that once a seedling bore, the fruit on it was a true representation of any future fruit it would bear. Does anyone have any information about this?
The genus Malus is extremely variable, which means that the seedlings of any given apple will not resemble either parent; I've read that 95% of seedlings that make it to maturity will be rather inedible. When John Chapman roamed early America, spreading seeds everywhere, he was planting trees for cider - "hard" cider, actually, since beer wasn't really available back then.
You'll have another issue with your seedling, too - size. It's not on any dwarfing rootstock, so it could get huge - or not. Size is variable, too.
So, regarding your seedling have "edible" apples at any time, the odds are low. And the first apples will be the same flavor as later ones. What you read may have confused the advice given to people who plant young, grafted, seedlings: remove the apples from the tree for the first two years or so to help the tree build a better root system, with no competition for resources from the fruit.
Here's an interesting BBC article on where the wild apples are: http://www.bbc.com/future/story/20160523-kazakhstans-treasure-trove-of-wildly-flavoured-apples