No no, sorry but this is completely wrong! There is no part in their license where they claim "map updates will no longer released if Maemo platform will be stopped"! Are we joking or what else?
If you sell a product claiming "free lifetime map updates" is your problem if the platform your program runs on is discontinued not a user problem!
And I also think their design and development skills are very poor if they are not able to provide simply the map files to all the versions of their program and for all the supported platforms (even the discontinued ones) not talking about their capability to develop a software for a set of platforms without the need of rewrite it for each one...they're very unprofessional and beginners...
I repeat, for the amount I paid for their program I don't see any convenience in submitting a lawsuit but If I paid more I for sure did it!
Last but not least if they are a company which makes software to sell it, they certainly loose customers if this is the behavior...for sure if I'll ever buy an Android or iPhone won't buy anymore one of their product so even their marketing capability is very poor...