According to this patent, yes.
Lexus has been busy filing trademarks for new model names. The Japanese luxury brand recently applied for the name RZ 450e, which breaks the company's current naming convention that uses either an S, C, or X as the second letter. And the RZ 450e isn't the only new model incoming for the Lexus brand; the company just filed for another name with the United States Patent and Trademark Office.
On September 8, 2020, Toyota filed for the names 'TX 350' and 'TX 500h' with the USPTO. Judging by the organization of those names, we expect the TX to arrive as a new crossover or SUV with a gasoline '350' and a more powerful hybrid '500h' variant.
Previous rumors suggested Lexus would introduce a new flagship SUV model called the LQ, which could replace the current Lexus LX 570. The TX trademark filing throws a minor monkey wrench into the LQ rumor, though with the popularity of crossovers, it's within the realm of possibility that two or more new SUVs are on the way. Judging by the numbers 350 and 500 used in the filing, we predict the TX isn't a tiny crossover with a small engine.
Lexus models with higher numbers tend to have larger or more powerful engines, like the 5.0-liter V8 in the LC 500 or the 5.7-liter V8 in the LX 570. These numbers do not always directly correspond to displament though, as evidenced by the 3.5-liter twin-turbo V6 in the LS 500.
In any case, we don't expect Lexus to pull out the number 500 unless the TX comes packing some serious power under the hood. This is not the first time Lexus trademarked the name TX, first applying for the patent back in 2012, then once again in 2014 for a rumored seven-seat crossover that eventually became the RX L. Those previous trademarks for the TX turned out to be nothing but rumors. Still, the last time we spotted Lexus trademarks, the UX came out shortly after, so don't be surprised to see a new model sooner rather than later.