The short answer is both yes and no. I'll explain why:
Lucian: Just push lane and b, I'm oom.
This right here is perfectly fine and not toxic. You are making shot calls, a.k.a. strategic suggestions, to your team. Making good calls and working together is how teams win games.
Blitz: (hooks and then loses fight)
Lucian: :/ listen bruh
This is.. technically toxic based upon interpretation, but I will say this is not. At this point I assume Blitz did in fact push lane as you had asked, but for whatever reason he decided to pick a fight. Now while not ideal, he has the right to make that choice even if it is the wrong call. While what you said is not obviously toxic, you made your disdain clear to your teammate, though perhaps you could have phrased it more eloquently. While I do not feel it is toxic, some people do see a phrase like that as toxic.
Lucian: Blitz roam around, we have like 0 synergy, don't want anything bad
Here again you are just making executive decisions, which is totally fine.
Blitz comes bot and gets caught out
Lucian: Listen... wtf
But here blitz clearly did not listen, for whatever reason, and you became more frustrated. Telling people to listen is fine, but when it begins to enter the realm of "What the f*ck why won't you listen to me" is when it starts to become toxic. I personally would not report you, but you should be more careful with your phrasing in the future, especially when calling out one player in particular. Some players (like that Hecarim for example) are easily triggered. I'm not saying you have to treat everyone with kid gloves, as that would be ridiculous, but just be mindful of what you are saying to others. :)
Hec: stfu luc, ur terrible, reporting for being toxic
TL;DR Don't be like Hecarim. What he said is toxic and reportable, what you said is not, but it is close.