Hello!
Currently, most level 50+ items have a level requirement that follows this pattern. It is both very noticeable and annoying, because you essentially need to wait for these thresholds to get an upgrade. You had nothing new for 10 levels, and suddenly you are able to wear all the legendary items you stored.
My suggestion is simple: shuffle a tiny bit these requirements (have 58 be 56-60 for example) to smooth the progression.
Yes please, it’s the steps of torment right now. There are empowered epics and faction gear in the mix too, but I can’t see the negatives of shaking the requirements around a bit.
I wholeheartedly agree.
The more you play, the more you stock leveling gear, the more it get noticeable, you struggle to advance during 5 levels and when you reach a threshold you are overpowered.
It is really a chore to grind between those levels with a complete set of subpar gear.
Ha! I am going to try to use that one more often around here…
This seems to be implying that - for most builds - Legendaries overlap and that accessing more Legendaries will allow you to replace older ones. I don’t think this is the case. Most of the time, once you get access to the first Legendary for your build, that’s it, you’re done for that slot.
Perhaps that’s a comment on Legendaries overall, though…
There are no better versions of your legendaries every 5 levels or even more frequently, so this does not actually work out.
Apart from that having items a few levels lower than your char is not really as noticeable as you claim. An item 2 levels higher than the one you currently use makes hardly any difference.
Possibly something to remember since the expansion is being worked on: please don’t make all the new items with a required level of exactly 90 
I get that certain “Epics” were designed to fill “the gap” when you don’t have a “legendary” that fits that slot. But maybe they should move the levelling gaps around a bit so you get to try them all.
Eg. fire 2-handers
Empowered Massacre - level 58
Infernal Brimstone - level 65
Shar’Zul’s Incinerator - level 75
Warhammer of Heavenly Judgement - level 75
Shar’Zul’s Worldeater - level 75
should probably be
Empowered Massacre - level 58
Shar’Zul’s Incinerator - level 65
Warhammer of Heavenly Judgement - level 70/72
Infernal Brimstone/Shar’Zul’s Worldeater - level 75
Level on Shar’Zul’s Incinerator should probably drop to level 65 anyway now that we have Worldeater.