Seriously so many posts about this, this week and last. Lets clear it up.
Legacy engram are doing exactly as designed. To give players a year 1 exotic that they do not have, this was mentioned in a weekly update afew weeks back before ttk dropped. Do people not read these any more?
The only year 1's excluded are vex and necrochasm because they are raid exotics. ( i say necro is a raid exotic because you still need the crux of crota (only gained in the hard crota raid) to ascend edilon ally).
While not all year 1 exotics have year 2 versions yet they will over time except for gally at least for the time being anyway.
What advantage do i have for a year 1 exotic i hear you ask. Well its simple shard it as it will still be in the blue prints and you need exotic shards (there is currenly no way to buy them now as xur no longer sells them) for exotic weapon infusions.
Please people read the damn updates and understand your unnessecary complaints are unfounded. The weekly updates are not there for the sake of it, bungie have not lied about these legacy engrams its just most people dont read them.
If anything xur needs to sell exotic shards again since they are need for exotic armour and weapon infusion. In the most recent update they have even stated they have now reduced the amount of these shards from dismantling exotics.