The introductory sequence is visible on the servers, but I also saw the intro offline. If I download the track using script Install & play here is not seen the annoying and delaying selection of opponents and others crap. The intro in this moment normally visible and the game runs like in old mode. But I can not run this mode manually and i dotnt know how do it. Moreover Install & Play does not work in this moment. I am very sorry that the intro does not visible, because I think the intro is the basis of the good track. I hope the intro will be visible again in the future .
I have found that the intro is now (after mp4 uptade) limited in time. I do not know exactly the time , because I use a Time retarder in track, but I think the time of a intro is set maximum to 15 seconds . Longer intro is cut off (Here i have a few problems in the old maps).
If anyone knows more, Please tell it

The current racing rather reminds official races on custom maps. Maybe the normal hunting mod coms later ??? idk.

Snake was discussing this on the forums a few days ago, so I'll say what I've learned from him:
Yes, you can watch the intros to a course if you launch the map via the GBX file and not the in-game browser.
Yes, there is currently a limit on MP4 intros. The limit is 20 seconds, but I think Snake mentioned that if you launch via GBX there is no limit on the intro.
Yes, the decision to not play intros offline as well as set a limit on them is extremely dumb. Hopefully Nadeo fixes this sooner rather than later.

I did pull this from memory, so if any of this is wrong please correct me.

Thanks for valuable information Arkive
Yes it works, When I run the track by clicking on the gbx file, The intro will be displayed , and the game works in the old mode. But there is a problem come , because with each new track started also new trackmania program. when i drove 7th track , there runs six other trackmania games in the background O_o. There will be definitely possible run the game with a parameter , but I don't know how do it.