@holon42 highly unlikely, since apples do better with cross pollenizing, so orchards are set up with multiple varieties & crabapples as pollen providers every 3-6 trees per row. it's possible but very rare to get true to variety from seed, BUT you may end up with an even better apple than Galas. just wait 10 years & see (and if you don't like the apples it grows, you can graft apples you do like onto it)
@holon42 there is a "wild" apple tree down the road that i need to get a graft from. it has the most delicious apples. it's obviously grown from an apple core someone tossed from a vehicle a couple decades ago