1) That the general level of Canadian English is reducing due to immigrants is ludicrous. You have a significant burden of proof for statements like that.
2) Transcreation is usually understood to mean the translation of creative/marketing texts where cultural and local norms are taken into account (think slogans, taglines etc.). It does not typically mean that you re-write the source text, adding new ideas and concepts. All you are doing in that case is fixing a bad source text. Sometimes we get blamed for translating a bad source accurately, so it's a fine line. But it isn't transcreation.
3) "Creative, complex text" does not make up the majority of a commercial translation operation's workload. Literary translation is a fraction of a fraction of the global translation demand. AI/neural net machine translation works for many, many commercial texts. I'd go so far as to say it works for the majority in the major language pairs.
Essentially it is recombining known good, reliable human translations in grammatically sound ways, even using idiom correctly where appropriate. The quality of the output depends on the quality of the input, and as such machine translations can be limited by the corpus it draws from. For example, the swathes of the freely available legal or regulatory texts it receives from the EU. These texts can use 'globalised language' at times, avoiding anything tricky to translate in the other languages that they are to be presented in, but that edges into a side issue of the globalisation of English/languages in general.
Overall, I hear a lot of this from the industry, "oh, it'll never work well enough to replace my job", but that's how you get blindsided. Accepting that it works well for major language pairs at this point is a good first step to accepting a changing industry.
That the industry is growing, and fast, may be down to any and all of a) increased awareness of translation's ROI, b) increased awareness of translation itself through the ever-present dream of ubiquitous, perfect babelfish-like translation and c) globalisation maturing into its final form. There's plenty of work for translators and LSPs for a good while yet, but spinning the line about how bad MT is does not help further the cause.