It does have the header and you can actually connect a Waveblaster or compatible MIDI daughterboard to it but, games will not be able to "communicate" with it, since it doesn't have an MPU-401 MIDI interface. And, all MIDI supported games, so far that I'm aware, requires an MPU-401 MIDI Interface.
This is probably the only manufacturer, that I'm aware of, that initially brought out a PC sound card with a Waveblaster header but without the UART MPU-401 MIDI interface.
I think that, initially, they were targeting a different market and you could, via MIDI software, then play back the MIDI instruments via a connected MIDI daughterboard.
I think there were professionally based audio cards with WaveBlaster headers as well but, this is not what were discussing here.
I would recommend you rather go for the I38-MMSN824 or I38-MMSN846. They are both 3rd generation Aztech cards, have excellent Sound Blsster Pro compatibility and have an onboard UART MPU-401 MIDI interface.
If you need drivers for either one, let me know.