I'm going to pass on this oppurtunity to be a smart ass. I'll even post something semi productive.
One of the bigger mistakes I made when I started to really get into the technical aspects of fighting games was I put too much emphasis on the numbers of frames. If you go into the game trying to memorize the exact number value of blockstun for every move in the game...... You're gonna have a bad time.
Classify them as neutral, slight neg, slight pos, big neg, big pos.
Now depending on what the engine has to offer and what universal tools the game has to offer the characters (like armor or backdashes or how quick most quick pokes are, or jumps or whatever) then you can come up with a sort of gameplan for each of the 5 frame situations and you can adjust to these situations on the go even if you're just learning a matchup.
If you use this method when learning matchups. Frames become much less daunting of a task and you can just ask "hey are you plus on that?" and they can answer "yeah slightly" or "yeah it's hella plus frames" and you can adjust on the fly. If you want to go back later and look at exact numbers to maybe come up with a better option for it, then cool. But you don't have to drown yourself in frame data to learn a matchup.
Also just realized I didn't really answer the question in the OP but oh well. Thug life.....
This could be partially true, but I still think you need to have a big category of things you know they exact frame data for. You need to know exact frames for:
-Your key footsie tools
-Everyone else's main footsie tool/pressure tool
-Your key punishers, and other characters'
-Your pokes
-Other people's pokes (within say, a margin of error 1-2 frames)
'Slightly negative" isn't enough to tell you whether you can beat out your opponent's 7-frame poke in neutral, or whether your main 10-frame punisher can punish someone else's 8 or 11 frame footsie tool. Not knowing things like that will get you killed.
So it's not to say "you need to know the exact frame data for every move and string in the game at Week 2", but for specific true, basic critical matchup tools you should be doing the math and not just guessing based on feel.