Best day for GNU Octave[1] and Sage Math [2], I suppose. Also Julia[3] language, probably.

[1] https://www.gnu.org/software/octave/

[2] https://www.sagemath.org/

[3] https://julialang.org/

Matlab is an industry standard on the same level MS Office may be so that's significant.

On the other hand, as said in the article it isn't irreplaceable and the long term effect of this ban may be to erode Matlab's dominance when no-one would have bothered otherwise...

I thought this might be of interest, as the affected researchers mention OSS tools as a possible replacement. A shame that GNU Octave didn't get a mention!