I have to admit that I have not listened to the new mix yet, but I find it hard to believe that anyone would want to change the tracks. Personally, I could see making the drums louder or even reducing the reverb and EQ effects on the vocals. But the album stands up pretty well after 50 years.
Like many people, I was disappointed at the time that the radio hits, Penny Lane and Strawberry Fields weren't on it. But after one listen, I didn't miss them at all. I was perfectly content to buy the 45 separately - which is what they wanted you to do.
Despite the chatter at the time, this is not a "psychedelic" record. Oh sure, it has a thin veneer of sound effects and unusual instrumentation spread across it, but it really is a British work - romantic ballads, skiffle songs and dancehall music with American rock clichés almost completely stripped out, perhaps the most British that they ever sounded.
I like it just the way it is.