I don't have any independent evaluations on hand but it is almost completely certain that SpaceX will not have any rockets landing on Mars in 2024 or leaving for Mars in 2024. Launch windows aren't every day, on average Earth-Mars transfer windows occur every two years. For SpaceX to "make it to Mars by 2024", they'd need to launch in 2020, 2022, or 2024.
- 2020 June: Starship has not achieved orbit yet. It is impossible that Starship and Superheavy will be ready to perform interplanetary missions in under four Months at the current rate of development. While extremely unlikely, SpaceX could theoretically scramble a Falcon Heavy which is capable of delivering a very small amount of cargo to Mars but as of the time that this is being written, SpaceX has announced no plans to do so.
- 2022 August: Optimistic estimates and Elon's aspirations put Starship in orbital testing at this time. According to Elon (and the SpaceX website), orbital tests for the Starship are supposed to happen in "2020" however it's most likely going to slip into 2021/2022 at due to "Elon time" and other complications in general. Even if Starship is fully operational, it is unlikely that Superheavy will be ready at this point and I don't think humans will be riding Starship just yet.
- 2024 September: At this point it is optimistically possible that Starship and Superheavy are capable of semi-regular orbital operations. The "Dear Moon" mission is provisionally scheduled for 2023 which means that SpaceX is hoping to have Starship be man-rated and capable of performing lunar missions (just flyby) by then. Personally, I think this date is most likely going to slip for man-rating but it's not unreasonable to assume Starship will be capable of delivering Starlink satellites to orbit in 2024.
So, in summary, No. It is almost impossible that SpaceX will be performing any Mars missions (outside of Falcon Heavy) by or in 2024.
The bigger problem, or something that's not addressed as much, is that SpaceX does not want to go to Mars, SpaceX wants to bring people and things to Mars. Elon has stated many times that he seeks to "democratize access to space" or "lower the barrier to entry" and that he wants SpaceX to be a transport company. SpaceX (as of 2020) has no plans for developing habitats, training astronauts, or building Mars buggies. In fact, they've stated repeatedly that the only thing they are planning on actually building for a Martian settlement or mission is the ISRU platform for manufacturing Starship fuel.