Since last update I opened at least 25 tokens with 4* and I did not receive any bonus heroes. Before last update I received 3/4 4* bonus heroes with just 10/15 tokens. I’m just unlucky or someone else noticed the same thing? 
If you read here,
https://forums.505go.com/discussion/29462
yeah people have gotten bonus 4’s since that update.
It’s a flat 5% chance each draw of legendary when its a 4, and a 5% chance once you get a 4 from other tokens.
There is no bad luck system, so the odds will remain that way. As you draw more they will approach or even surpass that 5% it’s just not a guarantee.
There’s just not a very high chance of you getting one is all.
With a 5% change of a bonus hero, you are expected to get one out of every 20 4* covers you open on average. So 0/25 isn’t too far off the expected rate of return. On the other hand, 3/4 bonus 4*s in 10 - 15 tokens is a much higher rate of return than expected, so you’re likely just regressing to the mean.
But don’t feel too bad; it could always be worse. For example, I still haven’t gotten a 4* bonus cover…
Ralph-Wiggum, I’m feeling your pain.
If everyone complains about falling below the advertised rates, we’ll run out of the internet.
Ralph-Wiggum, HobieCat76, I’m with you. I’ve opened ~50ish LTs since BoHe were introduced, not to mentioned scored some 4* from other tokens… Not a single 4* BoHe yet.
I have also miraculously drawn 5x 5* covers, but no 5* BoHe yet either.
I have won a handful of 3* BoHe, which is nice, but decidedly unsatisfying. Heh. 
my only 4 star bonus so far was from a heroic
I think they should treat 4s from heroics the same way they treat 3s from standards.
I have gotten 3 5* bonus heroes and 1 4*, that unfortunately was a color I can’t use (I was hoping to champ Peggy - but she is now 11/1/5).
Same here. No 4* bonuses, and had 1 3* BH from the start of the season. I don’t want to complain that much, but I’m personally won’t be upset if we don’t get new characters for a couple of months for an exchange of devs solving some major problems and bugs in the game.