The Karma nerfs in 6.15 are not a big deal for gameplay, but a big push in the direction of design
Quite frankly, removing Karma's ability to cast shields on minions is the last thing on that ability that makes her E unique and iconic/homage-worthy to her old self.
On gameplay, it doesn't feel like a big deal (could even be an unintended buff for supports, not mid lane Karmas). But in terms of being unique, Riot has just removed the last of what reminds us of Karma that was carried on from her old kit, even on design and thematic reasons.
The day Karma became FoTM, she was picked for the wrong reasons, mostly for being an overbuffed champion in her value. And she was nerfed for the wrong reasons - Ardent Censer + Mikael Crucible being changed to affect heal/shield values on top of Windspeaker's Blessings.
Nerfed for the wrong reasons, buffed in the wrong directions. Riot has screwed up her kit by mashing Shield + Move Speed together. Now that it scales with rank, her early game has also taken a hit. And honestly, I am confused about having a shield that provides move speed too. In fact I don't think there's any point in having a semi-tanky shield and moderate move speed anymore. I rather a full on beefy shield or a full on move speed boost.
Like I said again, the changes probably don't make much of a difference. But every step Riot takes with Karma is another step in to confusion and being lost. The team has asked players time after time "What do you think of Karma? We'd love to hear what you think about her."
But it almost feels like all of that engagement is just a facade to show players that they're trying to care about Karma, but have no intention of moving forward to make her better.