FYI. I note in this report, "However, as much as the light from TOI-849b's star would sear the
exoplanet, the scientists noted such heating alone might still not strip a gas giant's atmosphere down to nearly the planet's core. They estimated the star is about 6.7 billion years old. Given that amount of time, as well as TOI-849b's distance from its star, they calculated a Jupiter-like gas giant would have lost only a few percent of its mass due to stellar radiation to date...All in all, TOI-849b may give scientists a glimpse at what the core of a gas giant looks like. Future research may directly observe that core's composition by analyzing evaporated material in the exoplanet's remaining atmosphere. Further work may also investigate whether this exoplanet actually was a gas giant whose atmosphere was stripped away by the light from its star. "They claim that it's unlikely, but these calculations are hard to do," Raymond said. The new study, which was led by David Armstrong of the University of Warwick in England, has been accepted by the journal Nature. You can read a
preprint of the paper for free at arXiv.org."
Another report shows the core gas giant interpretation, is tentative as well, ref -
http://exoplanet.eu/catalog/toi-849_b/, "Armstrong et al. (2020) : TOI-489 b is probably a remnant planetary core. The equilibrium telmperature is computed assuming an albedo of 0.3."
The gas giant core view remains to be confirmed. If this exoplanet formed in situ, problems show up in protoplanetary disk accretion. Also the age calculation for the host star is not as straight forward as H-R diagrams for open clusters and globular clusters showing main sequence turn-off ages.