Personally, I think this suggestion is a great one. We've seen items in the past go from low level requirement to level 60 (ie: Withing Hour pre and post 1.04).
You've done it in the past, you can do it now too! The main reason being is that many <60 legendaries have a few unique, yet very interesting rolls.
Let's go with an example:
Beckon Sail (cloak):
+ 66-71 dex, + 6-7% IAS, + 3% life, + 1% crit c, + 1 random prop
At level 60, there is The Inquisitor :
+ 90-100dex, + 71-80 all res, + 12% mvt speed, + 235-599 life regen, + random skill ressource cost reduction, +1 random prop
The highlights of the first cloak are the IAS and crit c. The highlight stats of the 2nd cloak is the high all res and mvt speed. We can see that the first one is more offensive and the second one more defensive / evasive. However, right now, no one would wear the first one, since it's a lvl 53 item with although interesting stats, the rolls are pretty low. So how about bumping the Beckon Sail up to ilvl 60? We could give it properties like :
Beckon Sail ilvl 60:
+ 170-200dex, + 8-9% IAS, +1% crit c, +5% life, +1 random prop
And voila! Two ilvl 60 cloaks with complete different rolls. One offensive, one defensive. Opens up for increased skill variety and promotes build diversity.
Of course there are tens of other <60 ilvl legs with great unique stats.