No, we don't think this is OK. It looks ridiculous.
Remember that "textspeak" is just shorthand used to save keystrokes. I haven't seen anyone unironically use "2" instead of "to" since the days of flip phones -- on a smartphone keyboard, it's harder to type the number 2 than the word "to" because you have to switch to the numeral keyboard and then back.
Writing "u" instead of "you" is less common than it used to be, though some people still do it sometimes. But capitalizing the U is absurd -- remember, the whole point of shorthand is to save a small number of keystrokes, so you wouldn't waste keystrokes on unnecessary capitalization.
Any kind of shorthand like this looks ridiculous and out-of-place in a professional context, like a text message from a corporation. It signifies that you don't care enough to type out the whole message, which comes across as relaxed and casual between friends but as lazy and unprofessional in a form letter.
If I received a message liked this, I would immediately think it was written by some middle-aged manager who is trying to be "cool" and "relate to the kids." But a poor imitation of low-effort texting shorthand doesn't come across as "cool" at all; it's just silly and disrespectful. It gives the distinct impression that the whoever wrote the message thinks of me as "just a kid" rather than a normal, adult peer; as if I don't deserve the dignity of a normal, professional message.
Why this matters: SMS delivery is usually priced per message segment. Going over the 160 limit ~doubles the cost to deliver the text.
(Source: I am the CEO of a company which sends millions of text messages and avoiding 2 segment messages saves us thousands each month!)
All that said, the text from the above commenter's loan servicer is unprofessional nonsense regardless of its length.
How much is each customer worth to you?
Which is worse for your business - all your customers getting a cringey needs 2know if U wish 2stay in Autopay text and thinking that your entire business is unprofessional, or spending an extra $0.001 per customer per month to send them a message that reads F0rmatFunction can automatically pay your bill each month, but we need your approval. Change your mind? Cancellation is easy, just text "No" to this number. Respond "OK" to enable auto-pay! I'd rather get the latter for sure!
Sure, it's good to let those generating the messages know where the threshold is. Concise communication is best, sometimes you can be equally professional and just pick a different synonym or structure, and save the company some money. But sacrificing quality of a $20/mo service to save $0.001 per customer seems unwise, even if it adds up to a thousand-dollar bill.
you're thinking really hard about paying your student loans now, so it worked. who doesn't understand what's going on? doesn't sound like it's your loan-servicer, to me.